If a developer doesn't care if their games look like crap then why would they care about game play.
Excellent game play and excellent graphics (also sound) are, more often than not, brothers and not enemies in the gaming industry. Even on the Wii some of the best looking games has the best game play as well, SMG, MP3,etc.
It's no accident that both MGS4 and CoD4 has both great graphics and game play.