I think a lot of people make very foolish assumptions that the well informed "core" gamer necessarily prefers genres like FPS; and that unsophisticated "casual" gamers will necessarily prefer genres like mini-game collections. The truth is that the bulk of all game sales above a certain level (regardless of genre) come from mainstream gamers, who are only going to become aware of a games existence through word of mouth or an advertising campaign.
Realistically, the demographic of a console might have some impact on the sales a game would achieve on that system; but this impact is fairly minimal, and is less of a determining factor on the final sales of a game as several other factors that are currently being ignored. Basically, if you kept the quality, production values, marketing, genre, release dates, competition, and notoriety (basically new IP vs. established IP) roughly the same between games released to two different platforms you might see a 10% difference in sales that could be attributed to the demographic differences of the platform.
On the other hand, we see endless comparison between Wii games and HD console games where the HD console game was higher quality, had greater production values, a larger marketing budget, a more well known IP, and a better release date and people are blaming the demographic for the poor performance of the Wii game.
