I listened to Jordan Peterson and what he was talking about was not particularly radical - instead of a modern, rational, scientific, agnostic view of the world he had more pre-Enlightenment Dark Ages notions about the Bible, the supernatural and such. As premier learning institutions aim to be devoted to rationality, the scientific method etc., it's not a conspiracy keeping him away, he's just preaching things they are not about. I'm sure he could go to some backwoods corner of Arkansas or Kentucky or something where people would be more receptive to these ideas about the supernatural.
It's also putting a number of people into the same boat. People may agree or disagree with Steven Pinker about various topics, but at least he makes rational arguments. Search the New York Times and he is treated as an intellectual worthy of respect, although points may be right or wrong. I don't see him being excluded from anything. If anything, the nurture over nature argument is what is blocked from the establishment discourse.