I never thought I would have to post an explanation of why I don't swear, but in the last few months the issue has come up in a number of different contexts, and I've realized a lot of people either don't have a clue about what's going on in my head, or have jumped to the wrong conclusion about it.
Here, then, is the simple truth of the matter.
I was brought up by parents who didn't use even the mildest oaths, and who gently but firmly corrected me when I said things like "Gosh" and "Darn". "Holy [Insert Random, Inoffensive Noun Here]" was right out, since only God is holy. Even "Rats" was deemed suspect, since it was obviously a substitute for some kind of stronger language. And the TV went off immediately if anyone used the Lord's name in vain.
This might sound like my childhood was horribly repressive, but I love and respect my parents, and have always had a great relationship with them. Swearing was one of very few areas where they really took an unyielding stand, and since I never heard a single oath or crudity come out of their mouths under any circumstances (and that's pretty impressive seeing my Dad served in the British Navy during WWII), I think I would have absorbed the idea that swearing was inappropriate even if they'd never directly said as much.
The upshot of all this is that even now that I am an adult and no longer answerable to my parents, I simply don't have a lot of rude words in my vocabulary, and no particular impulse or temptation to start saying them. Instead, I use a limited, idiosyncratic, and for the most part decidedly G-rated range of exclamations. The Internet has given me access to handy acronyms like "OMG" and "WTF?" but I feel kind of guilty using even those, since I know what they "really" stand for. Even my fiction writing is occasionally hampered by the realization that Character X would swear under normal conditions but most of the time I can't bring myself to let them do it, so I have to find a creative alternative like "He spat out a fierce oath." I even feel uncomfortable quoting material that contains swear words, since it's too much like the swear word is now coming from me instead of the original speaker or writer.
However, I don't think of myself as specially virtuous for not swearing: it's just not me. Other people swearing in print or speech doesn't bother me for the most part, unless it's extremely gross or profane. I can even find swearing funny when it's done creatively, as in humorous writing. After all, sometimes there just isn't another word that's emphatic enough.
The only kinds of swearing that really upset me are racial slurs, crude sexual epithets, and (especially) blasphemy. Although I think I would have to say something if someone was using offensive racist or sexually degrading language in conversation with me, I really haven't had that happen very often, so it hasn't been an issue. But blasphemy, I hear all the time. And while I'm aware that most people don't mean anything hurtful by it, and aren't even thinking about what they're saying, I don't think I'm overreacting to find it offensive.
Mind you, 99.9% of the time I don't say anything when somebody blasphemes the name of God or of Christ, either because the person speaking doesn't know I'm a Christian, or because they weren't speaking directly to me, or because it was said when others were present and I feel the subject would be best addressed with the speaker in private. But for the record, if you're talking to me or know that I'm there and you're tempted to use blasphemous language, I'd really prefer you didn't, thanks.
Of course, this is just in case you actually give a crap care what I think. If you don't, then... as you were.