When the Wii U was first being conceived, Nintendo wanted to make it a console that could appeal to current Wii owners, newcomers, and experienced "Core gamers". The Wii was a massive hit, but it was often stereotyped as a casual and non-gamer console with an abundance of fitness games, party games, and mini-game collections. Especially since more and more developers were moving into HD, and thus, moving their projects to PS3 and 360.
So with the initial Wii U reveal, Nintendo wanted to make sure that the Wii U would be a console that can bring the core gamer back. The controller being a standard gamepad with a screen on it, games like Darksiders II, Batman Arkahm City, and Tekken announced to be coming to the console at launch. EA's "Unprecedented Partnership". It seemed like Nintendo was using the Wii U to make the Wii brand cool to PlayStation and Xbox gamers.
https://www.youtube.com/watch?v=upgzaZ5nk-o
Of course, it was a pretty lame attempt. The console launched and the games didn't look much better than PS3 or 360 (in fact, they often ran worse). Numerous games that could technically run on it were just straight up not coming to it. And Nintendo's talk of it being a console that could appeal to the "Core gamer", was undermined by the mostly-kid and family centric marketing.
I feel the initial Wii U positioning was a bit of an over correction in trying to win back the "core gamer", while at the same time, not going far enough. A giant controller that was too complicated for the Wii casual audience, yet too cheap feeling and obtuse for core gamers. A sort of neat online system that still wasn't nearly as well rounded or polished as Xbox Live or even PlayStation Network. And games that were mostly just upgraded versions of Wii games in HD, and games already available on other platforms, but with pointless GamePad gimmicks. It felt like Nintendo was trying and failing to be the main console for all people.
Obviously, it didn't work, and was one of the contributing factors to the console's failure. I think Nintendo realized that they're just not good at creating a console that targets core PlayStation and Xbox gamers since the two attempts they tried (GameCube and Wii U) failed. Which is why the Nintendo Switch smartly avoided this mistake and primarily targeted indie games, Japanese developers, multiplayer titles and casual games.
