You are speaking with ignorance. Go back and watch his game against Oregon this year and tell me his team doesn't have competent schemes and priority on certain aspects of defense. Again, would you expect Ball St. to shutout a power school because their coach is a defensive minded guy?
No.
Talent is about 70% the problem. The rest has to do with his offense putting up more points per game, and have allowing other (more talented) teams more drives per game. Of course he is going to give up points.
If we both were in charge of top 30+ schools, you go hire Mike London or Pat Narduzzi, I'll take Mike Leach. I can assure you by the end of a certain time frame you would see he's no where near "garbage".
He had ranked, even as high as #5, teams at TTU of all places, going against a pretty good Big 12 at the time.