I’ll give you a concrete example. I used to enjoy a popular anti-Obesity subreddit. People in it were impolite, but it was never worse than old-fashioned “your momma is so fat” type of humor.

It was banned from Reddit for being “hate speech” and in fact you can no longer suggest that obesity is something to be ashamed of —- on nearly any platform! Including GitHub. (but you are allowed to mock mock cigarette smokers or meth tweakers).