I love their games, but the Wii U just had "arrogance" written all over it. Bad, cheap hardware, a gimmick that didn't hook people instantly the same way as the Wii Remote, but gosh darn it you were going to learn to like it, a refusal to present a modern product, instead recreating mistakes made by their competitors years ago, and still lacking in key features requested over and over (Microsoft redesigned their entire console interface once, maybe twice in the time Nintendo has dithered around), an unwillingness to echo basic features present even a generation ago (SD card support massively limited, what the hell is going on with the Virtual Console, etc), the list goes on.
I do have a Wii U (found it on clearance at a Sears for $200 a while back), I do have several games for it, and I like those games, although 90% of the Pad "justification" has fallen flat with me. It either strikes me as something that could have been done without very easily or adapted to a TV without issue (even stuff like Zombi U's bag rummaging), or is so forced that it artificially creates a detriment in the product, just to "solve" that issue, or needlessly complicate the game. (Nintendo Land is full of these.) Then there's all the chatter about Remote Play, which just says to me "I want a more powerful Vita that plays Nintendo games."
For their next console, whatever it is, I want a modern product. They don't have to be competing with the PS4, or the Xbox One, but I want something with modern design sensibilities, smart features, without blatant, clunky limitations right out of the gate. It doesn't have to be a technological powerhouse, but it shouldn't be hobbled by a weak CPU or slow memory. The interface doesn't have to be Windows, but it should be able to do the expected things out of the gate, not six months after launch, or a year, or two years, or we're still asking for it. ("Folders, praise the lord!") If they're building a dedicated gaming machine, yet we'd get more features working more solidly if they had built an Android box running Google's "Play Games" service, they've messed up. Maybe they shouldn't be the ones building the front end anymore. They can have their list of "Here's what we need it to do, and these are the unique and quirky touches we want to do." But maybe they need to stop trying to reinvent the wheel if they can only make octagons.
For what it's worth, the eyetracking addition on the New 3DS to improve the 3D impressed me greatly. I want more of that.