Adventure games like Grim Fandango stopped selling so developers stopped making them. Same thing happened to scrolling shooters, side scrollers, dungeon crawlers and a whole host of other genres. Also, some of my favorite game developers fold or drasticly scale back after commercial failures like Okami and Psychonauts. This is why I care about game sales, I don't want to be left with nothing more then a bunch of derivitave sequels.