Yeah, why are you allowed to play tennis but you aren't allowed to kill people? Why can you say John's a good person but you can't say he molests children? Why can you shout "fore" on a golf course but not "fire" in a movie theatre?
There's always a limit. Choosing to stop your for-profit web service from enabling bigotry and murder seems a pretty low bar here. Let me know when it's being used to prevent the discussion of ideas such as Marxism or veganism or solar power or whatever which might upset the current power structure.