What it takes to prosecute someone with a crime is very different than what it takes to win a civil case.
I view the "kicking a perp off campus" as comparable to a civil case. If there the evidence suggests there is a better than 50% chance the guy is a perp - I want him off the campus.
So - what you're saying is that you are totally OK with your sister/daughter/friend being sexually assaulted by a guy who has a history of "probably" sexually assaulting other girls even if the police know about it just because the prior victim doesn't want to keep reliving it and have to report it to yet another agency.
Me - I'm not OK with that.