The point of the restrictions/punishments was to deter from this happening in the future, and not just the pedophilia but rather any criminal activity and schools' covering such actions up.
Are you really that thick? It happens everywhere, so fuck it? Why not just let it be? What exactly are you arguing? I'm confused here. Because regardless of the prevalence (or not, really) of pedophilia, the NCAA still has to act because the school clearly didn't. Penn State decided that it's football program was more important than Sandusky paying for his crimes. That's why the NCAA got involved and if you ask me, Penn State got off light.