#5 is an good point that seems to be underrated in this thread. The GBA was a JRPG factory at a time when JRPGs were at their peak popularity in the West, helped in large part by a deluge of NES/SNES ports and remakes, many of which were brand new to non-Japanese gamers. We got ports/remakes of things like Final Fantasy I-VI and Tales of Phantasia, and countless others.

If I could add a #7, I'd say that something the GBA had in its favor was that it was now the sole outlet for smaller developers/projects that still wanted to produce simple 2-D low budget games. The game industry in the early 2000s was still in that "2-D console gaming is a thing of the past, 3-D is the future!" phase where 2-D games were considered passé, but not on the little handheld that could. So game makers could pump out GBA games way faster than on any home console and take more risks. That's how we got three Fire Emblems, two Advance Wars, two Golden Suns, a thousand Mega Man Battle Networks, three Iga Castlevanias, two Metroids, and so on.

I never saw it in that way, but damn, yeah, Mario Sunshine, Wind Waker, Star Fox Adventures, whatever they did with DK, neither of those were well received at the time, and even today the only of those games that bounced back is WW. But I disagree with Double Dash, it was actually one of the good games in there, along with Melee, TTYD, Metroid Prime 1 and 2 and many others.

Anyway, my answer is simply that the GameCube had to go against the PS2, the GBA didn't. Xbox didn't fare much better than the GameCube, with Halo or not.

Also, at that time, the pervading feeling in the gaming community was that Nintendo was kiddie (for children) and uncool. People at that time wanted GTA, MGS and DMC. They wanted "edgy", mature games. Nintendo was seen as a cutesy kid-game company, so there was nothing they could have done to change things.

That's why their handheld did well. Because kids played handhelds. Also: $99.99

Nintendo was stuck in the red ocean in the console wars during that time (remember this was pre-Wii where they hadn't reinvented themselves yet in the home console space and had yet to really separate themselves from Sony and MS outside of having pressure-controlled triggers and a lunch box console with a handle). Whereas in the handheld space they were essentially alone in the market, and also had a larger library with more and better games overall. The GameCube felt more niche as a whole - it had the stigma of being a more "hardcore" as well as kiddie console, while Sony was more mass market with their PS2, and MS had the "cutting edge" tech and superior online angle to tout, which at least drew a little more attention.

On the surface the obvious answer - and it has been given a lot of times already - is that the GBA had no competition worth mentioning; Nokia's N-Gage fell into this era, but that device sucked ass.

Digging a bit deeper, the thread's question is more interesting if we assume that both systems launched into a similar competitive environment and ask which one would have been more successful. This strips the GC of the biggest excuse that is made for it while it hardly affects the GBA.

After all, the GBA had good battery life, had an SP revision that fixed the one glaring omission of the original GBA (the lack of a backlight), competent ports of noteworthy 8 and 16-bit games, solid original games and of course Pokémon which was still riding high. There's simply no reason to believe that the GBA would have not been successful if it had had to compete for real.

On the other hand, the GC was home to many installments of big Nintendo IPs that were either disappointing or left fans with mixed reactions. Remove the competition and it's still not looking good. It doesn't work the way that if there was no competition, the GC would have sold 100 million units due to the market having no choice, because the market always has the option not to buy anything. 3DS vs. Vita proves this to be true, because the Vita quickly vanished while the 3DS still could never get close to the sales pace of the GBA, let alone the DS. Of course the GC would have sold more than the 21m it did in the real world, but forget about 100m in the hypothetical scenario.

The bottom line is that the GBA was much closer in matching the market's expectations towards a Nintendo console than the GC could ever dream of. By now we've had enough console generations to safely conclude that any Nintendo console can become successful based on Nintendo's output alone and regardless of how strong its competition is.

The anti-piracy was the main reason, for sure. And the "bigger" RAM could also help in many cases, YES, because they reduce the number of times you have to search for the same things, over and over. 

But... mini-DVD was faster:

The inner parts of an optical disc always reads faster than the external parts. The smaller discs tend to be faster because laser can proceeds phisically faster to search and deliver the info it needs in every moment. But, obviously, those discs have less capacity than the bigger discs of the same era and same technology (CD/DVD/BR...). So, it ends to be just a balance of performance/capacity.

In any case... Gamecube discs were VERY fast by 2001 (not as fast, though, as charging a game from a solid memory media, like an SD, using some MODERN external ports exploits for the GC, for sure... But was faster than the normal DVD consoles. 

I will put an example: in Wind Waker for the original GC, you would see how the game will load the islands (especially the taller ones, the more noticiables) from the distance. As faster as you approuch to them from the sea, using your little boat at full blow of the wind, the GC will make appear a very simple silhouette in the horizon, and will load different "shadows" of that same island until... at some point... it wil load a super low res model with color in the distance, and better models of that island will happen to load... until you finally arrive... or bypass them very near.

Using the same game, loaded as an iso from an SD reader using one of the Gamecube external ports (for example, one of the memory card ports, or the officially unused SP2 port)... that same process is much more organic, faster, and enjoyable, and you can see how all that process is loaded in a much faster, succesful, indistinguishable and "natural" way (and without any possible mini-dvd reader little noises in the background).

That means Gamecube Mini-DVD was technically a fail? NOT EVEN NEAR, it was the better and cheaper commercial system to fastly load a huge chunk of data (like an island in that game) by early 2000s. In fact, it was good enough to enjoy the game experience traveling across the sea.

That simply shows how Gamecube could process the data much faster than its own mini-DVD reader could deliver it (working as hard as it can). In that Wind Waker situation, having more RAM than PS2 did not help that much (the info of a full island was too large for the RAM to be charged full-time in it, so the process repeated every time an island appeared in the horizon when you did a long trip (so... you got lots of little noises from the reader working at full capacity XD)

BUT... with a normal DVD... that process would have been a little more messy for the Gamecube... especially if Nintendo had not deriberately put the "island data" in the inner parts of the disc... specifically to avoid too large "time consuming" loading problems in real time game experience.

At the end... though, as many third party GC games ended to be just PS2 ports, or originally multiplatform games in the best scenario... not many games had the mini-DVD characteristics in mind during its development for GC, so... Gamecube Mini-DVD was not so-well used as it could have been, like in WW.

But was faster, anyways.

To echo the thoughts of Shigeru Miyamoto from some ancient interview with Famitsu that stuck with me - Nintendo failed with the Gamecube on a creative level, and that translated to commercial failure. He expanded by saying that instead of setting the trends, they were following the trends of others. Also according to Miyamoto, this bad creative direction included their software strategies at the time.

In other words: GBA was still very much a Nintendo system while Gamecube was more a reflection of what Sony was doing with Playstation. The kiddy image was because GBA was the standard - it had accusations of being kiddy as well, but no one cared. But the Gamecube was the imitation - so the contrast was made sharper, and the PlayStation fans it was targeting weren’t impressed. And, to be fair, the Gamecube was quite a kiddy looking piece of hardware: the purple colour, a controller that looked like a toy while the box itself resembled a child’s lunchbox. On top of that, the software they were using to push it were games like Celda and Sunshine, neither of which were the direction people wanted either series to go - especially after showing a more Twilight Princess and action packed version (I don’t like Twilight Princess myself, but that was the expectation).

The controller wasn’t particularly Nintendo-like, but more of a perversion of the PlayStation dual-shock controller littered with needless complexities that seemed to be more about fitting a certain aesthetic than functionality. It was poorly designed. The L&R buttons were squishy and made an irritating plasticky springy noise when pushed; the Z-trigger was easy to misplace because of its tiny size and weird positioning; the C-stick seemed like it was missing its nub; the D-pad was tiny and stiff; the diamond facebutton configuration was replaced with a big green button in the middle of a tiny red button and two oddly shaped grey buttons that made traditional button combos near impossible making it unviable for many Virtual console games (go no further than Mario World to see what I mean), and other games had to be compromised in their control schemes (like SSX games) or cancelled altogether (like certain Capcom fighters).

The issue that made me abandon the Gamecube wasn’t any of the annoyances with button sizes or placement, but it did have to do with the controller. The shape of it forces people’s hands to conform a certain way, which caused a lot of pain on the edges of my hands for action games - especially Mario Kart Cubed and the GC port of Soul Calibur. Keep in mind, I am unusually tall and have unusually large hands, but I’m I’m not alone in this. As a side note, my favourite console of the generation, the Dreamcast, had a similar controller issue, but not nearly as severe, and I could adjust my hands allowing me to play games like Soul Calibur for hours. But this was my main reason for abandoning the Gamecube. To this day, I have an aversion to controllers with those more rounded designs.

Overall, I’d say it’s because the Gamecube was a flawed Playstation with poor aesthetic choices, missing features, and a lack of the creative trendsetting that made Nintendo great in the past, and great in the future. Sony is going to beat Nintendo at making a Gamecube-like console on their experience and expertise. Just like Nintendo soundly defeated them in the motion gaming and handheld fields.

The consequence of Gamecube was that it was the more expensive R&D, marketing, and development. This is why Nintendo had its first red fiscal quarters in decades during that generation despite the handheld division selling quite well; Financially, Nintendo had fallen off the boat and GBA was the life preserver while Gamecube was a cinder block tied to its leg. It’s also the console I believe Miyamoto was most critical of, as I don’t even recall him badmouthing the Virtual Boy.

I'll never understand the failure of GameCube, it's a great console. I guess the PS2 was a menace and just totally overshadowed everything.

The problem with the Gamecube was that it was just completely out of touch with the market.

Gamers didn't want kid's cartoon Zelda or Mario cleaning up graffiti at a resort with a water pack or DK played with bongos or a system that looked like a cheap toy. Bringing that to the table when the competition had GTA and Halo was like showing up to a gunfight with a pool noodle, it's no wonder the system fell flat.

Why are you hyping up Halo and shitting on Wind Waker which sold comparable numbers to Combat Evolved on a smaller install base? Granted Wind Waker is no Ocarina of Time, but selling like OoT on a smaller install base was a tall order. It did manage to beat Majora's Mask.

Nintendo had a number of GC games selling close to Halo level in that era. And critically, they had Metroid Prime which is an all-time great, and released a good sequel to it as well. Nintendo's software was still comfortably superior to Microsoft's including Halo.

Xbox didn't beat the GameCube due to Halo. It did it because it was the better marketed and cooler device with superior third party support, monster specs, and a special appeal to PC gamers. Of course Halo contributed but it wasn't a bigger factor than Nintendo's software, and was nowhere near GTA's level.