Yes, but people are allowed to do that. I don't think "free speech" means what you think it means. It's a comforting idea that other people are too immature/emotional/dumb to consciously think about an opposing belief, but that wasn't the case here. There's no obligation to hear out a side that would do you harm given the choice. w/r/t letting people say unpopular things, the university did decide to host him in the first place, which represents the university's commitment to some form of free speech. Individual people should not be subject to scrutiny for protesting something they disagree with.