On Pc you sit on a desk...your posture is optimal this way for using a mouse and a keyboard.For the consoles... so "mostly" consoles are near to the Tv screen ( i hope we dont have to discuss that

The player needs to have the tv screen in sight in order to play the game.. so whats near your tv as an option to sit down? Yes your couch. A couch is not as high as an office chair...and your living room table is supposingly on the same low level as your couch. So using a keyboard and mouse on a console is not a good thing for your back/spine. Its rather unconfortable. I tihink for consoles the wireless pads are the best solution.