It definitely goes both ways but I think it's important to recognize that _most_ people don't fall for those fringe beliefs. Keeping ties to the people that do fall into them gives them a lifeline to pull themselves out.

Additionally, I find the thought process of the person that wants to shut down those "dangerous" ideas pretty repulsive. It seems implicit to me that they are trying to protect those that are lesser than them. There's an implicit superiority there.