I think it's a combination of 2 things:

1. Rogers is an adequate, very football smart game manager.

2. This offense will limit anyone to a degree. In the Big 12 and Pac-12 they had guys breaking away for big plays- that happens alot less in the SEC. Teams are playing soft pass D and then running downhill and blowing people up. The defensive philosophy against Leach has changed over the years. We cant usually throw quick because of the coverages against us. So everything has to develop. It's really hard to throw against 7 and 8 players play after play. Rogers almost never gets the luxury of going only against 6 in the Secondary as most QB's get often vs a 4 man front and 1 blitzer.