I agree with @Lilly here. People can say quite nasty things and claim its freedom of speech 
For example… I login to a community to read and contribute about its purpose eg. Meta = Discourse. If people began posting things under the argument ‘freedom of speech’ discussions would derail and quickly become off topic/inappropriate. I’d much rather those posts be moderated.
But ultimately, it all comes down to what the staff allow on a community. When a user creates an account they are agreeing to comply with the sites terms of service, in which somewhere (hopefully) are content guidelines.
You would definitely expect a professional approach if it was a branch of the gov but again my points above stand.