It's the same reason why Lane Kiffin got jobs at UT and USC after pathetic performance at Oakland and playing a major part in questionable practices while an assistant under Pete Carroll.
In the basketball world, look at Calipari, for God's sake. He might be a pretty good X's and O's coach, but he gets a "pass" from just about everyone in the media other than Bob Knight. While watching ESPN and all other sports media, all everyone talks about is his "great track record" at Memphis, UMass, etc. No one seems to care that he left both those programs in deep trouble with the NCAA. Calipari continues to get the big jobs despite being a scum-bag. This is, unfortunately, what college sports have become. The NCAA needs to close up and go home. USC will be getting no penalties for their shenanigans and Calipari will probably get coach of the year.