I agree, yes profanity can help emphasize an important point (I do it myself), but some people use it constantly in place of "Umm" "Ahh" "Err" and it makes them sound like a primitive slack-jawed rube.

Also, some people can't seem to control it (or have any decency) especially when my young kids are around. Really ruins the situation when trying to use a public basketball court, skate park or being near a group of teens.