It's all about the games and the visibility of the games.
Think about it. Imagine a Wii 2 closer to PS4/XBone level of power (and close to the same price as the Wii U due to the scrapping of the pad) which launched this last summer with all of the major games released from last Fall until now (notably including NSMBU, Zombi U, Lego City, Monster Hunter 3U, Game & Wario, Pikmin 3, Blacklist Best Edition, Rayman Legends exclusive, Wonderful 101, and whatever other third party games would have existed). Anybody who could complain about that launch lineup would never be in the market for a Nintendo console in the first place. Like, ever.
Then from launch in say July or August until Spring 2014 we would have Wind Waker HD, Sonic, Wii Sports Club, Wii Fit U, Mario 3D World, Mario & Sonic at Sochi, DKC, and Mario Kart. All of those are just the exclusives. Take any of the games you want out of the launch lineup and spread them around if you want, too. Hell, take NSMBU out completely and release it in the middle of 2014 to make a seamless flow of hits into the Fall 2014 release schedule. Note that none of the games I listed are pipe dreams, rather they are all games that have already released or will be releasing soon for the system.
The difference between this and what actually happened is that you skip out on literally ten and a half months of incredibly negative media attention. In my mind, the wasted year is what is killing this console right now. Can Nintendo release and market enough games in enough time to get the Wii U out from under this oppressive cloud of negativity? We will know by the time Mario Kart's numbers are reported. My guess is no.
Either way, in hindsight, I do believe that it would have been better to keep the console off the market for half a year rather than throw it to the wolves and let it get ripped to shreds instead.