Yates is far from terrible. Remember the win against Cincy? That didn't happen on its own. He out played Matt Ryan his first start. He played last year like a rookie. Pretty much how the rookie QBs are playing this year.
But, to play devil's advocate here, the more playing time he got the worse his
play got!
On the other hand, to be pragmatic, I believe Yates suffered as the season went on from too much information at once. At first he was relying on his instincts and his knowledge of the paybook of course, but then he has Kubes, Dennison, Knapp, Schaub, Leinart, Garcia, Dellhome, and God knows what other players in his ear 24/7 "coaching him up."
I remember reading all the practice quotes from back then and thinking that these guys are putting too much in his head, and sure enough, week after week his play faltered, in turn causing Kubes to dumb down the playbook because of his own monster.
Of course we'll never really know, but I think it's as sound a theory as any, especially since Yates, at the start, was doing as well, or better than a number of his peers and even Hall of Famers during their first years.
While we're on the QB topic, though. If Vick stays in Philly, maybe we could have a shot at Nick Folles? I would love to see this guy in a Texans' uniform.