I actually used the system I believe how Nintendo intended ... as a life style device.
I would use the Wii U game pad as my TV remote and quick load into some SNES Virtual Console (F-Zero!) during commercial breaks. I even used the video chat function. It was alright. Miiverse was neat too.
The thing is the OS was slow (checking sports scores took too long) as Nintendo isn't an OS company.
In a world where the iPad doesn't exist and iPhones didn't proliferate so quickly, there would probably be something there as a living room device, but as that wasn't the case, the Wii U just felt like a lame duck.
The design of the Game Pad was also ugly, it looked like a kid's tablet. Both Nintendo and MS banked hard on the casual lifestyle aspect of the Wii U and XBox One (Kinect) and it backfired badly on both of them.