It's not so much that conservatives think they have to have control over everything. OK, some do.
I think this stems from professors like Ward Churchill. Since he is in Colorado there was a lot of discussion of him and liberal professors on the radio. I realize this is just anecdotal evidence, but there were quite a few people who called in who said that they or their children were not necessarily graded for their work in class, but for their agreement with the professor/teacher (this went into lower levels of school, too). If they dared to disagree with any statement, no matter how outrageous (i.e. Churchill's notorious statement about the "little Eichmanns" on 9/11), they were either failed or their grade substantially lowered. These "teachers" were not encouraging open debate, because anyone who didn't share their view was wrong. That is not teaching young adults to critically think for themselves.
If the shoe were on the other foot, and there were a rash of University Professors who wouldn't accept any student who said that Bush and his policies were wrong, would that be a problem? If they berated and belittled anyone who didn't agree with the war in Iraq? If they preached daily about how gay marriage is going to pervert society and lead to bestiality, or how abortion is murder? Would any of that be acceptable in a place where you are supposed to be trained for the future?