the thing is, some people can put those things aside, but others cant.
being offended is not a choice
moderation exists simply cos being offended is not a choice.
just like the roadcode exist cos not everone is a noble driver
a hostile forum simply loses its participants
those small prints when you register on a forum generally states you can conduct by the codes of fairplay and nice behaviour, and conduct deemed unwanted will be edited or deleted
bu registrating you agree , thus accepting moderation