Short answer,
He targeted kids who were from small towns and depended on scholarships to be there. Nobody ever swung on him because he was an extremely well respected doctor and, in their minds, nobody was going to believe a child over an incredibly liked and tenured professor of medicine. So some kept quiet.
Many did speak up. Near 200 formal complaints had been filed, when it was all said and done, and the school didn't do anything about it. Actively covered it up. This includes Jim Jordan.