How about I buy whatever game I wish to play on whichever console I own where it makes the most sense.
No way I am buying any online multiplayer games on Wii U. It doesn't have any system level party chat. That's a deal breaker. Also I like to be able to party chat with friends even when playing single player games, so another reason why those games are better on my PS4. There is one exception to this and it is if that game supports up to 4 players for local multiplayer. In those cases I will choose Wii U version of the game since it is the only console I have where I have 4 controllers.
So examples are things like Rayman Legends and Sonic All-Stars Racing Transformed (actually supported 5 players on WiiU).
So whats left? The Nintendo exclusive software. As long as they keep making those or releasing VC games I am interested in, I will keep returning to Wii U for some play time.
Worrying about 3rd party success on Wii U is Nintendo problem and 3rd party problem... not mine.