Why is profanity used?
Generally for shock value (no shock, no value)

Thank you .. I am reminded of a story about Lenny Bruce getting up on stage one night and repeating the F-word non-stop for ten minutes. Even as long ago as this was, the shock value wore off very quickly.

I am also reminded of my high school pal Randy Reid mimicking a fresh new grade 8 student (we were lordly grade 11 students at the time) who alternated the F-word with ordinary words in a sentence to prove how 'tough' they were. I laughed so hard I couldn't speak.

I consider Perl Monks to be a professional Perl salon; unless it's in context (like someone quoting MJD in their .sig), profanity is not used, because I think we're all brighter than that.