There are two distinct populations (in UK), those of poor vocabulary who use swearing all the time and don't seem capable of speaking in a nuanced way. And those who have the vocabulary to not swear, can still express themselves without expletives but choose to use them depending on the company/context they're in.
I found as a teenager that I'd swear to try and appear cool, and when I lacked sufficient nuance to my vocabulary to clearly express my feelings, and decided I wanted to do better.
I don't really care if you swear - except in front of children (because they have to learn not to swear in the wrong context when they can get in trouble from others who are more conservative) - but unless you demonstrate otherwise I'll assume it's lack of decent vocabulary.
Almost all people I've worked with who've sworn a lot (amongst general company) have had very low levels of education.
I don't really understand the whole "these words are shocking" attitude, eg cunt, people give simple utterances too much power.
0) http://hackersdictionary.com/html/The-Jargon-Lexicon-framed....
I would be curious whether high-vocab swearers diverge from low-vocab swearers in how they actually use bad language. In my experience, even my high-vocab friends drop f-bombs in substantially the same way that lower-vocab friends do. I don't buy the "lack of vocab" hypothesis, because no one smurfs swear words as a smurfy substitutes for inadequate vocab, but as for the "lazy language" hypothesis, I think it's possible to use curse words as a crutch even if you have the capacity to do otherwise.
And fluency doesn't necessarily indicate usage. I could rattle off many taboo words with which I am acquainted, but that doesn't mean I choose to use them.