NOTE: this an opinionated piece, it's not my intention to troll or to incite a flame war. 

I believe Wii U is destined to become the most disliked and the biggest failure (sales wise) for Nintendo since Virtual Boy. So what better way to analyze this thesis than by comparing it the Gamecube which is still the worst selling (mainstream) Nintendo console so far. 

Personally, I thought the Gamecube was pretty cool, I don't think it deserved the low sales. In comparison, I think the Wii U DOES deserve not only the negative press but also the poor sales. Lets' compare them:

1. Graphics: GC was pretty advanced for its time, competing with both PS2 and Xbox for best graphics output at the time. In contrast, Wii U is a generation behind the PS4 and XB1. 

2. Price: GC launched for $200, Wii U launched for as much as $349

3. Third party support: GC had pretty strong support with Capcom releasing some of the best RE games ever. While it didn't have as much support as the competition, it still had publisher interest. In contrast; third party support is all but dead on the Wii U. 

4. No gimmicks: GC had no gimmicks, it didn't try to force anything new or untested on gamers. It featured a standard wired controller which I found comfortable to use. In contrast, the Wii U is forcing players to use the gamepad which many find repulsing (myself included). The new skylanders stuff that was announced is also turning me away from the console. 

5. First party titles: I personally didn't like Mario Sunshine, I thought it was really boring. I know Zelda was also controversial but later received a cult following which led to the re-release on Wii U. Metroid was also a stellar title. So far it's too early to tell what the quality will be on the Wii U but I know many have praised Mario world. I doubt we'll see two new Zelda games like on the GC and I also doubt we'll see any new Metroid. I think the GC will probably come ahead as the winner here in the future.

Based on the above; it's easy to see why the Wii U is flopping hard. It just doesn't feature the qualities and value of the GC. Sales are justly deserved in my opinion. 

There's the option to use a Wii Mote for a lot of games, but I get the point. Anyway, for me it all comes down to the games (because that's what I use consoles for) so once Nintendo and others stop developing games for the Wii U I'll be able to decide whether I think the GC or Wii U is better. Also, isn't the Virtual Boy the worst Nintendo console?

I don't think it's fair to include the Virtual Boy in the calculus since it was a failed experiment and not really a mainstream console. The GC is the best comparison. 

No fool, that was the Virtual Boy.

Not a mainstream console. 

What's a Virtual Boy?

OT: I think the Wii U may end up with the better library of first party games thanks to games like 3D World ( which is better than Sunshine) and Mario Kart 8 ( which seems to be better than Double Dash)!

Uhh, but the topic clearly says worst Nintendo console? Virtual Boy is a Nintendo console, so it doesn't matter if you consider it a failed experiment or not. It's still the worst. Also, I didn't say anything about the GC being a bad comparison. :/

It is the worst Nintendo console. Objectively.

I think the Wii U's major failings, price and lack of third party content, will ultimately solidify its position as the worst Nintendo console. No, I'm not saying it's a bad console, I'm simply saying that it will be ranked as the worst when all is said and done.

The Wii U's main crime isn't having a gimmick, it's having an expensive gimmick. Of course, Nintendo's business practices deserve as much blame as the console itself. A better plan and more effort could have translated to a moderate amount of success.

Err, what!? The Gamecube is absolute garbage compared to the Wii U! Vastly inferior graphics, no online play, no backwards compatibility, no multimedia features, less controller options, no eShop, no off TV play, poor design, no free game included, and so ons!