If you agree that the rule-setting is unnatural under such context (i.e, the context of an online community, dealing with humans and human nature), then you would agree that you should first fix your own expectations.
If you read my comment about the Scott Peck's framework, then you can see that at the first stage, humans are generally nice to each other in any group setting. This is a modern condition: the consequences of civilized societies. But humans also tend to reach the second stage, where they are totally not nice to each other. If you read him directly, you'll get the better idea.
This argument of freedom of speech, or lack there of, is misguided and misplaced in my opinion. It tends to come up at every opportunity (every normalized social network now initially had this argument when they started in the beginning - and we're still having this misplaced argument.