Reader "Wariostro" responds with the following rebuttal. The third paragraph is especially insightful:
I've debated this so many times that I'm becoming a broken record, but I can't resist at least joining in a little here: while your post seems to be aimed more at humor and inciting the flames, I have to say that Wii Music is, indeed, a much better game for musicians.
I enjoy Rock Band with friends, but no one should have any illusions about it: it's Dance Dance Revolution for the physically lazy, coupled with the added fantasy of being in a band. It's fun to play the little mindless button game while listening to music, and more fun with friends, but it doesn't have much of anything to do with musicianship.
Wii music lets you play with actual musical ideas: not only combinations of instruments, but how, for instance, to elevate the chorus of a song, play with a familiar melody or chord progression in such a way as to tease something new out of it, experiment with different percussive strategies, etc. It's damn hard at first to produce something great, but that's no excuse for most of the gaming world to give up and call the game shallow. It's only their own musical skills that are wanting.