Talks about salt; becomes the saltiest of them all. It is okay if you didn't understand, I forgive you.
If a "Super" Wii U was made, I don't think things would have changed all that much. You are acting like the lack of third party support has been a recent trend, and not something that has been steadily getting worse since Gamecube, and was even worse with the N64. Those two specifically are consoles that were similar in power to the consoles of the time, yet both struggled. You could argue it had to do with their software format, ie cartridge and minidvd, but their handling of those consoles seemingly put more strain on their already strenuous relationship with 3rd parties. When you have troubles with third parties, you get less third party games. So you have arguably, about two and a half console cycles where the third party output was less than optimal. I count Gamecube as half, as they were still getting some pretty great third party titles for awhile.
With the Wii specifically, many Nintendo fans felt burned with their new business direction seemingly abandoning them, and they either quit gaming or found new consoles/PC. Is this the crowd you are talking about that would come back to a powerful Nintendo console? Because they weren't enough to make the Gamecube sell more than a newcomer in the console business.
I don't think the Wii U would be in a much better position if it was more powerful. It might be worse off. At they very least, the tech behind a more powerful machine would make the console be priced like the PS4 or Xbox One. And considering there is no reason Nintendo would have ever made a traditional console after the massive success of the Wii and DS, it would probably be at least as expensive as the Xbox One due to the Gamepad or whatever. Maybe Bethesda wouldn't have dismissed it so early on though, but if the sales were just as bad I'm sure they would dismiss it anyway.
I cannot explain to you enough the absurdity of PS/Xbox fans jumping ship before the next iteration of their console of preference is released. It would need a shit ton of third party support for that to even be seriously considered, which I doubt would have happened. Also no one is talking to the friends on Xbox Live or PS Home or whatever and saying "Yo, that New Super Mario Bros Wii U and/or Pikmin 3 look mad good, but that shit is to jaggy for me to drop $300+ on."
This is why I said that Nintendo needs to mend its relationship with both third party companies and console gamers before it can be successful again.