Looking back and reflecting on it now, the decision to not use CD-ROM for the N64 was a killer and that really put Nintendo in a bad position, but with Sega imploding, Nintendo still had a reasonable chance to gain ground again with the GameCube. 

This is a nice article on the story of the GameCube (initially codenamed Dolphin):

https://dromble.wordpress.com/2014/01/07/dolphin-tale-story-of-gamecube/

To me the thing that really killed the GameCube was not launching it in 2000. Nintendo initially had planned to release the system in 2000, but didn't have enough games. This gave Sony like over a full year head start, and also gave Microsoft time to get the XBox and Halo ready. 

This is Yamauchi speaking around 1999:

 “We would like to release the Dolphin closer to the PS2, but since we’re aiming for the Christmas 2000 shopping season, I don’t think the time difference is that big of a handicap,” said Yamauchi.

Of course, Nintendo being Nintendo they couldn't stick to this release date and had to delay to 2001:

“It’s always the case with Nintendo, the hardware is already completed, but the software is not,” said Imanishi.

I think this was the killer. Had they been able to launch in 2000, I think they would've been more competetive with the PS2 even though the PS2 would've won and they would've consolidated a lot of the split that the GameCube (22 million) and XBox (24 million) had into one, so I think GameCube would've sold 45-55 million if they could have launched it for fall 2000. XBox would've been way too late, and Sony didn't have a great first year of software either. 

Yes they would have great success with the Wii a few years later, but in doing so they basically surrendered the entire traditional market to Sony/MS and they weren't able to even keep the casual audience, so they kind of locked themselves out of both markets. 

If I could go back in time and tell them anything it would be to pull Zelda: Majora's Mask, Perfect Dark, and Conker from the N64 and put them on the GameCube as launch titles and launch in 2000 no matter what. 

Stop it, you're making me depressed over a future that never happened.

We could have had 3rd party games by now.

There's pros/cons to both sides. On one hand the Wii was incredibly successful for 4 years, but dropped like a rock afterwards. 

On the other hand, had the GameCube been successful, it likely would've resulted in a lower peak but much longer than 4 years of success. 

There likely would be no Microsoft XBox in the business and Sega would still be out, leaving Nintendo to probably sell 50-55 million GCNs, then with the Playstation 3, if Sony had made the $600 error, Nintendo likely would've pounced on that and won that generation or at the very least made great inroads. So maybe a hypothetical "GameCube 2" sells 70-80 million units like the XBox 360 did. 

Motion gaming still could've been a thing on a hypothetical "GameCube 2" or even the GameCube itself ... Nintendo was researching the idea as early as 2001 (see the article), it was originally intended for the GameCube. 

Regardless of the console side, the PSP was coming no matter what, so Nintendo would have had to repsond to that one way or another. 

I've heard it said that when empires are failing they often do the one thing that is the exact opposite of what they should do. That was the Gamecube. But it's not where things went off the rails for Nintendo. That was clearly the N64. Not having CDs and losing the exclusive 3rd party relationship they had with key companies like Squaresoft did dramatic damage. N64 had a strong western following, but there were already signs of older gamers preferring the Sony brand toward the end of its life. With the release of PS2 Sony was on a role and it would have taken a truly dramatic showing from Nintendo to even be considered as an option no matter what it did. Things GCN did wrong:

-A message of a "gaming machine" when others were pushing a "multi-media device". It's hard to grasp right now, but back in the day it was still somewhat new for adults to want to game. So calling something a media device/DVD player made it way easier to accept. Major fail on Nintendo's part.
-Purple fisher-price look
-Baby-sized discs
-Weird versions of Mario and Zelda
-Late launch
-Loss of Rareware, Retro not able to replace.

So yeah, they went off the rails entirely there. But even if you correct all that stuff, they still had to contend with the fact that Sony had Final Fantasy and GTA as exclusives. That's an impossible hill to climb. You're talking the biggest western title and the biggest eastern.

Nintendo would have had to not only correct GCN's flaws, but also go beyond and get aggressive and made some decisions with foresight. What could have turned things around:
-Secure Rockstar North as a 2nd party studio and endorse the production of GTA (haha)
-Bought Bungie and had Halo as an exclusive/Goldeneye follow up.
-Been aggressive and supported Square when it was bleeding money in 2000, and brought the FF brand back to Nintendo exclusively.

Those things COULD have made GCN a worthy PS2 challenger, but let's be honest. They were on the exact opposite of Nintendo's actions at the time.

The Xbox wouldn't have been affected much from being the only one being released one year after the PS2. It was a totally different demografix already back then. If anything they would have stolen sales from the PS2 because the PS2 had a very wide demografix with many people playing arcade racers, cartoon platformers, Guitar Hero and other casual/childish games.

Either way, your alternate history is essentially pointless lol

Plus I thought u were a very future oriented guy, to say the least.

They didn't have to beat Sony that generation, Sony still could have won running away. 

What Nintendo absolutely DID have to do is get the heads up on Microsoft and beat MS badly enough to maintain a solid no.2 spot. I think that was doable. 

Even with other mistakes, just launching a year earlier with Zelda: Majora's Mask and Perfect Dark instead would've effectively sealed the XBox's fate, it would be too late and far behind not just one, but two consoles for developers to seriously get it behind it (this is the same problem NX is now going to face if it tries to engage PS4/XBO directly, or how Atari Jaguar/3DO couldn't do anything against SNES/Genesis). 

Nintendo also likely could've capitalized on some of Sony's own mistakes, namely making a very hard to develop for system. In the first year this could've been a difference maker, but since Nintendo gave Sony an 18-month headstart that gave Sony such a huge lead that all 3rd parties basically fell in line and were forced to support the PS2. So basically all the effort to make the GCN easy to develop for was all for nothing because they just let the system sit on a shelf for an entire year because software was not ready (piss poor planning). 

Nintendo got Resident Evil away from Sony as it was, who knows what else they could've taken away had they actually launched closer to the PS2 and been somewhat competetive. 

Plus if you move Majora's Mask into the launch window as a GameCube game, you kinda take care of the toon shading problem Wind Waker presented too, because people would've gotten more of a traditional Zelda in the OoT style first (albiet Link is a kid through out MM) and then it wouldn't have been such a big deal with WW to do something different. 

I think that gen would've ended more like this:

Playstation 2: 120 million, GameCube: 50 million, XBox: 10 million 

Had Nintendo been smart and launched in 2000.

Not going to lie... the original post is ludicrous.

Nintendo's biggest mistake was breaking their deal with Sony for the SNES CD. Every other mistake was a side bar to this mistake.

Nintendo's smartest move was using Gunpei's ideology to create DS and Wii. Unfortunately, they stopped paying attention to Gunpei once they got to the top and the mistake of the SNES CD snafu has outlasted the positives of paying attention to Gunpei.

This makes Gamecube a push as Wii would not exist without it.

Also, Gamecube had far more mistakes than its release date. As a matter fact, the release date was hardly an obstacle at all. People did not want a purple, "lunchbox" with a controller that they thought was less than adequate and childish looking. Wii launched two days after PS3 and we all know how that went.

I think I do state in the OP that not making the N64 a CD system (or cart + CD system) was a huge mistake obviously. We all know that. But they still were in decent shape to regain decent footing had they acted better with the GameCube. 

Yes, the Wii had tremendous profit for 4 years, but 4 years worth of profit is not enough to sustain Nintendo. By making the Wii they effectively basically gave Sony/MS the entire traditional console market, which would've been OK if they could have maintained their new market, but they completely lost their entire new market too. 

That's largely because casual/fringe gamers are inherintely unpredictable, we see that even with things like Pokemon Go ... it's something that's highly popular for a period of time, but then starts to drop off very quickly too. Pokemon Go is still doing well, but you can see it's starting to cool off and could fall off in a year or two. Kinect on the XBox also is the same story. 

They needed to do well enough with the GameCube to keep Microsoft out of the business. Had they bided their time, likely Sony would've made the same $600 mistake with the PS3, because they got obsessed with winning the next movie format race, that would've been the opening for Nintendo to then move in and take over. 

No, I'd say it was the N64. While it had legendary games, it got creamed by PS1 and was the first time they were manhandled globally.

The N64 is when Nintendo started going downhill.