Certain schools/coaches just seem to be branded "good" programs and are held above suspicion. It blows my mind that there are two recent incidents of players and their families receiving significant financial assistance and/or gifts from third parties and (relatively) little has been made of that.
I think part of the reason, unfortunately, is that USC is effectively a pro team in LA and receives the lion's share of football coverage, and the NCAA is not inclined to disrupt that any time soon. It is so rare for a big-name school to be located in a major city (Georgia Tech, da U, and [somewhat] Northwestern and BC seem like the only exceptions off the top of my head), and as long as the NCAA can be a major player in the second largest media market in the US, it will be beneficial for them. I'm sure at some point they'll have to take action, but don't be surprised to see these types of infractions go unpunished for at least the near future.