Just going to quote the rules/FAQ, might give you an explanation to your problem/rant:
Q: Someone insulted me. Why aren't you deleting his post/thread?
A: Possible (since we don't have the time or resources to check) insults are also allowed as long as they contain any kind of constructive opinion, info or something else substantial and aren't off-topic. For example, posting something like "you are dumb" will be deleted as it contains no meaningful content. However, if the post is somehwere along the lines of "You are dumb. This is wrong because this website/thread/etc. has explained it's not right", it's in most cases accepted.
People are probably going to say shitty things to you on the forum, which sucks, but that's the reality. If you really think that the post violates this, you should just report it.
Let's just remember though that just because we can throw insults at each other doesn't mean we should. Let's try to be civil y'all