As (one of) the board's resident USC follower(s), allow me to chime in on this:
First and foremost, Chow wasn't fired at USC. He left after the 2005 Orange Bowl victory over Oklahoma to pursue a job as the offensive coordinator of the Tennessee Titans under former Trojan, Jeff Fisher.
Second, I am not entirely convinced that Chow is that legendary of an offensive coordinator. I say this because Lane Kiffin as OC got more production out of the same offensive players in the 2005 season than Chow did in 2004. Where I think Norm Chow really shines is as a QB coach. He is probably one of the best in the country at teaching QBs to read defenses.
Third, as others have pointed out, he runs a Pro Style Offense with a dedicated run/pass balance. He likes to run plays with a two-back system. He has absolutely no experience with scrambling QBs.
One positive is that he literally wrote the book on using screen passes to effectively counter an over-agressive pass rush. I forget the name of his text, but it was a fascinating read. You literally felt like you could play QB after reading it because he broke everything down so clearly. It greatly enhanced my knowledge of the game since I suddenly understood why, for example, the QBs point to the defensive line before the snap. I used to have a PDF of the text; I'll post it up if I have it for those who are interested.