It's good that the there is a practice of censorship in the arts. Think about it, if there is completely no control of what is being shown regardless of whether in dance, theatre, music or visual arts, its going to be a complete mess. People are going to get hurt, traumatised and shocked. Sure, some things missing might not be as interesting as before but at least it protects the people, the public.
Playwrights have the right to write about anything they want, and you as the audience should not have to have the government tell you what the masses should and shouldn't watch that's a personal endeavour and you can make that decision personally. That is why there are descriptions of the play when buying tickets.