True. However, for every simulation game it seems that there are at least two or three first person shooters.

And the big ones like Grand Theft Auto are very popular. Back in 2007 they had already sold 50 million units, making over a billion in revenue. And that was two years ago. With a cursory check I couldn't find recent sales stats.

Btw World of Goo is a great game and really shows that fun doesn't have to be violent. ;)