I hope we don't only sing about existing things. Rhapsody of Fire would go away forever.
Anyhoo, don't give a damn about profanity. Like anything, I only get annoyed by it if there is an overabundance that makes it seem like they aren't trying (works for movies, comedians, etc. also). If it's just in there, likely as emphasis or because that is the natural way for the person to talk, works for me. There are in fact plenty of songs where switching the profanity for "nicer" words would ruin them completely.