the point your missing, is that when games are co-developed. PC owners get a poor console port of the game, that doesnt fully utilize all the extra processing and graphics power available in a PC.
If the game is developed for PC (thus utilizes all the PC powers) then is ported over to console (removing some of its orginal features) it works fine. Its when a game is developed for console, and then no extra work done to create the PC version, that it all goes wrong