swear words are embellishments(as well as verbs, nouns and adjectives) that convey a lot of emotion.
compare:
'this program won't work!'
versus
'this fecking program won't work!'
the second example suggests I am rather more upset about the situation than the first. and that I'm irish, because nobody else seems to use feck as a slightly milder alternative to reproduce.
it's not that I don't know enough words to otherwise convey my disappointment(I am fond of 'thrice-bedamnèd' but it's a bit flowery and would get me laughed at in certain circles) but that nothing gets quite so much emotion across as a word considered 'obscene' by some people

personally I don't consider it 'censorship', rather 'over-delicate sensibilities on the part of some people'. it's easy enough to dodge a wordfilter after all.
and do bear in mind I come from a busy forum where you get more of a reaction if you deliberately avoid swearing by self-censorship. it's heavily moderated, admittedly, but only because it has 100,000 members rather than because people like to say 'gently caress'(the word censor that replaces reproduce if you're not logged in).