Maybe because the University might be sued? Schultz was the Senior Vice President of Business and Finance.
One of the department that reported to him was the University Police. Neither Schultz nor Curley (nor Paterno nor McQueary) ever reported the 2002 incident to the University Police or any law enforcement or child protective agency. Neither Schultz nor Curley (nor Paterno nor McQueary) ever tried to find out the name of the child anally raped in the Penn State football showers.
The apologists who say that Schultz was the head of the Penn State police are simply wrong. The head of the Penn State University Police reported to Schultz. The head of the FBI may report to Barack Obama, but that doesn't make Barack Obama the head of the FBI.
Schultz was there in a CYA mode. And he did so effectively . . . for nine years.
McQueary was the one who should have called the cops since he was the one who saw it. With Paterno, it became whisper down the lane and he reported it to the people to whom he was supposed to, and I imagine who thought would do the right thing.
BTW, if you look at the Grand Jury Report you'll notice that another incident of child sex abuse by Sandusky was observed by a janitor, who couldn't bring himself to make a report. Maybe if we try real hard we'll find a way to blame Paterno for that.