Nobody, aside from hardline communist trash and religious zealots that should be hanging from the lampposts are advocating censorship.
I, and most of the people I have talked to believe in a platform for all. I WANT communists to go on the stage, so that they can be laughed off it. I WANT people to watch videos about the benefits of socialism in venezuela. I WANT people to tell me about their racial purity, so that I can show them the genetic history of the world.
For all their faults, I cannot deny that hardline leftists are good at one thing - creating right wingers.
Also, as a side note - despite the Overton window being stuck for a long time in the left isle, the majority of people are centrists.