if you stub your toe or drop and break a plate when washing the dishes, do you say, "oh, dagnabit"?
I think this is the main point to make... humans use words to express themselves. Strong emotions require certain words... and if none exist, then a person will make up their own. It's a psychological necessity.
As a matter of course these words aren't for polite company, and kids have yet to learn social norms, so we have parents and teachers giving rules about language that are meant to be outgrown... and also I assume that while adults understand the necessity of vulgarity on an instinctive level, many are too stupid to understand it beyond that... so among certain groups people will go around preaching that these words and even those who use them are somehow intrinsically bad... which is ridiculous.
If they don't go around and say the word is bad...
then what's the point of using the word in the first place?
Sure it's "bad" in the sense that it's not polite and only for certain situations, but I mean they'll say it's bad in a spiritual sense.
When our llama is drunk....asterisks flows like water