Calling someone a fucking ass doesn't convey anything of what your point is. In those cases where someone absolutely can't be reasoned with swearing at them isn't going to change the situation, actions might, but words won't.

Another mentioned about it being needed in some cases where the situation doesn't merit politeness. In those cases though what's gained by charged emotional responses if you're going to engage at all? It's wasting energy on things that have no benefit to anyone.

Cursing really only has any meaning because we give the words power. Similar to slurs against various groups, they only have bite because we give them meaning and history. I'll give this challenge, give me an instance where any given situation was benefitted by their use though, outside of mere expression of rage or hate what benefit did it add?