User base between Xbox one and Wii u is just 2-3 million apart. So hardly a big gap.
Demographic wise this type of game won't sell that much on its first week. This game is meant to play local coop with plastic instruments so it is an expensive game.
I have friends who bought this game on the wii with all the instruments of course crazy to buy this game without those anyway. For the Xbox and ps owners they didn't even try to buy this game. In not saying it is the Trend to all but there is a user base for a particular genre/game.
Still not a big lose but if the development was similar with pa and Xbox they surely have thought to build it for the wii u too.
If they want the crowd, hope they can have those old plastic instruments(PS3/xbox360) run on ps4 and Xbox one. Game would sell better.
