The majority of this article could be replaced by a simple realization most self-aware people come to in their teens: when what people want to believe conflicts with the facts, the facts usually lose.
That's still not a reason to limit free speech. The article isn't even a failed attempt at justifying limitations, there is simply no attempt to present the other side of the argument: why limitations on free speech are so very dangerous. Without that the article is just meaningless puffery. I expect better from a university faculty member but that this half-argument is put forward in a national newspaper by a university professor does go some way toward explaining why so many university students have such overly simplistic views of life.