Umbran said:
Is that a coined euphemism?
From
Swearing: A Social History of Foul Language, Oaths and Profanity in English, by Geoffrey Hughes;
"There is also the interestingly exact correlation between degree of taboo in verbal usage and the degree of taboo in actual public exhibition of the referent."
This means that basically, the less people want to see it done--or the more they SHOULDN'T want to--in front of them, then the more offensive it is likely to be.
The same book talks about inuration by readily-observable violence, sex and over use of the swears, themselves.
The same thing, I think, is true of racial slurs and the like. THAT, to my thinking, is the reason that we should refrain from swearing in front of our little ones. My nephew popped out with f-word at the dinner table, one Thanksgiving, and everyone ignored him. Good or bad? Hard to say.
As to why we, as Americans, generally don't think that swearing is such a great thing, we can probably point to our Puritan ancestors. I may be wrong.