Universities boot people out for other reasons which are not actionable in a criminal (or even civil) court all the time. Getting shitty grades, being a disruptive asshole in a class on a regular basis, and so on, can end your university career.
So, with that in mind, "creeps everyone the fuck out and is probably a rapist", isn't such a stretch. I would not put someone in jail for that for any length of time. But, I don't know if "deserves jail time" is the right comparison. Maybe "I would fire this person, if they worked for me" or "I would kick this person out of my social club" are more apt.
Now, I think that someone so expelled should have an easier time getting into another university than they currently do. Right now it seems that getting expelled because a university tribunal found you responsible for an alleged rape carries, for the purposes of college admissions elsewhere, nearly the same consequences as being an actual convicted rapist. This puts too much faith in the judgement of some other university's tribunal, which bring me to my next concern:
These tribunals are too often full of shit. There are a few horror stories going around and you've probably read a few. Some places I think are not requiring a high enough burden of proof. The regulations and standards at the federal and state levels ought to be improved, and in light of the fact that sexual violence on campuses is on the decline, the improvements should result in fewer students being expelled, not more.
But, in principle, I think it's fine for a university to do this, even if the accused rapist could not possibly be convicted in a court of law.