Censorship always prevents debates. The number of things which are explicitly banned from discussion may technically be small, but the chilling effect is huge. And the fact that ideas and symbols are banned is—correctly! - taken as evidence that they can’t be beaten by argument, that people are afraid of the ideas. Also, naturally, the opposite side never has to practice their arguments, so they look like weak debaters because they are.
Censorship always prevents debates. The number of things which are explicitly banned from discussion may technically be small, but the chilling effect is huge. And the fact that ideas and symbols are banned is—correctly! - taken as evidence that they can’t be beaten by argument, that people are afraid of the ideas. Also, naturally, the opposite side never has to practice their arguments, so they look like weak debaters because they are.