And if people use a wiimote only to play with it sideways in the seldom event they are playing a 4player (rare enough) game with four players around the tv (even rarer I guess), that would totally prove my point.

The wiimote or let's say, what Nintendo tried to achieve with motion gaming, became a thing of the past the moment they went back to dual stick controls. Supporting the wiimote for some MP games won't change that.
Even I, who really doesn't like dual stick anymore and much more prefers mouse/wiimote/move for most genres except racing, wouldn't even think about buying a WiiU for the WM+ support. You buy it for the gamepad and for new gameplay concepts and experiences which are the result of the touchscreen and a second display. The moment I'd play ZombieU with a WM+ I#d only feel like I'd miss out the thing I just bought a console for. And I'm pretty sure 95% of gamers will think or feel the same way out of good reason. There goes your Wiimote.