Speech. 
I don’t feel like curses are anything more but an honest emotional expression. I actually doubt most people flag at all, to me it mostly seems that some people flag as if they were most.
I can tell you that “asshole” definitely isn’t a reason why I’m getting flagged and I have posting histories to prove it. 
It was a long, hard road until we’ve collectively reached this point, btw. 
The problem really isn’t people who are cursing. The problem is people who don’t, despite clearly exposing feelings of anger expressed informs of ■■■■■■■■ accusations, tons of rage-typed typos and passive aggressive behaviour. They’re not honest. They’re hypocrites, liars and they’re hiding something.
Political Correctness especially is nothing but fascism disguised as good manners. These usually are the same people who cry for censorship, cry “think of the children” and cry for safety. The most toxic pieces of ■■■■ ever.
See also:
I honestly wished more people would come here for interesting discussions, but the toxic assholes don’t want that to happen, especially when it comes to certain topics.