The console business is a "razer and blades" style business - the game publishers have to give a huge percentage to the console makers. Although PC games are more niche, the publisher gets a bigger cut and there's pretty much no second-hand market stealing sales. Also, while console games require a huge amount of compliance testing (meeting the console makers' specific demands/requirements), you can pretty much release whatever broken, buggy shit you want for PC (hell you can release something like "Big Rigs" if you want), although obviously, similar requirements/licensing costs are required for content distribution systems like Steam/GFWL.