Why? What's the difference between a PC and a console, exactly? Enlighten me.
We all sit her staring at TV's with our keyboards on our laps. Replace the controller with a mouse and get a bit closer to the TV and we're already there.
:^/ With consoles, they're identical. The same amount of RAM, identical processor architechture and clock speeds, identical graphics chips, the same operatinng system, etc., and the developer can optimize his software exactly to the hardware he know you have.
With PC's they're all different, so the developer must fashion his wares more generically, allowing the various operating systems to adapt it to different processors, graphics hardware, RAM, etc.