The only argument I've ever heard is that swearing is the sign of a lower intellect or smaller vocabulary.
In the words of Stephen Fry: "Utter nonsense! The people I know who swear the most tend to have the widest vocabularies!"
In the words of Tim Minchin, in The Pope Song, about the speech in which the pope protected the priests that molested church boys: "if you don't like this swearing that this ************ forced from me, and reckon it's just moral or intellectual paucity, then fuck you, ************, this is language one employs when one is fucking cross about fuckers fucking boys."
In the words of me: "It's fucking ridiculous. Swearing is fantastic; just a little slip of a word can cause such shock to the prissy, stuck up and backwards morons that are still so pathetic that they're offended by mere words, and it can make you feel so much fucking better when you're angry or just need to vent."