There was a great article in last week’s New Republic on why we curse and why we care. Steven Pinker:

… perhaps the greatest mystery is why politicians, editors, and much of the public care so much. Clearly, the fear and loathing are not triggered by the concepts themselves, because the organs and activities they name have hundreds of polite synonyms. Nor are they triggered by the words’ sounds, since many of them have respectable homonyms in names for animals, actions, and even people. Many people feel that profanity is self-evidently corrupting, especially to the young. This claim is made despite the fact that everyone is familiar with the words, including most children, and that no one has ever spelled out how the mere hearing of a word could corrupt one’s morals.