Straw man. It is not censorship to decide that an audience would be better served by hearing another speaker. And it is not censorship to decide that a speaking venue would be better used in another way than hearing somebody ride his tired old hobbyhorse yet again.

You have a right to stand on a bench in the public park and speak your opinion. You don't have a right to stand in somebody's auditorium and speak your opinion. You don't have a right to be paid by somebody to stand in his auditorium and speak your opinion.