As a kid I've been rather uncomfortable about the use of swear/foul/abusive words. Initially I found it as a sign of badness in a person, but some of my good friends changed my perception on that. Till date and perhaps for many more years to come, I haven't been able to speak a swear/foul/abusive word to anyone! It just doesn't feel right.
I often argue with my friends that swear/foul/abusive words are used by those who don't have enough language skills or lack confidence in the same, or those who want to express themselves using a common lingo, a word or two rather than speaking out the whole thing... and for this argument of mine I receive(d) a few abusive words in return!
I did mumble the swear/foul/abusive words to myself when in a desperate or urgent situation and it felt good, but then I asked myself later, was it really necessary?!
But honestly, these words can add to the style factor of one's talk... when the protagonist shouts the F-word at someone, it amuses me a lot !!