Ok, I understand what you’re saying, saying “f you” is faster & easier.
2 (now 3) points I want to make:
I getting this sense that instead of speaking to someone, it’s to let off steam. As you put it, “it’s cathartic to say.” I find that telling of a weak character to need to blow off steam because of a conversation they’re having.
Since cursing usally indicates aggression, I can’t help but think if you are short on time then making people feel aggression is not the smart thing to-do.
Cursing is just as impercise as using wit. I don’t know it helps other than maybe show rage in a spit-second responce, but people have said “f you” in different kinds of context for different kinds of affects. At that point intead of “f you”, you can say “leave if you going to say such trash.” You could be more direct than using some vague swear word.