The problem wasn't the name. It was how the console was presented and marketed: everything was about the gamepad.
Even Nintendo sent mixed messages in the E3 2012 press conference. "This is Wii U". And then Miyamoto picks up the gamepad. It happened.
There was confusion, all right. And it was fair to point at that confusion as the reason that lead people to not see it as a successor to Wii.
The real problem came when it was clear that despite the brand confusion, the main market for Wii U's existence simply wasn't there. And it wasn't there even when the confusion was taking place.
You could have called it Wii 2 and things woulldn't be that much better.
Nintendo was counting on "someone" who wasn't there to begin with. MS never had that problem - even if they had called it "XB 360 now with more power" - because their market was there.
