In my opinion, in today's popular culture profanity doesn't hold much weight at all as an effective tool for communication. While profanity is often used by people who are communicating something passionate and emotional, it is used just as often in a completely flippant and emotionally detached manner.
For people who are offended by profanity it may evoke a negative emotional response but I find for people who are comfortable with profanity, it carries very little weight or meaning except for the fact that the speaker couldn't be bothered to come up with a more meaningful word to use.
I will acknowledge that because most of society is so lazy in their use of language, there is a strong relationship between a person who is communicating passionately and the frequency of profanity usage. This is why movie writers so often lace passages of emotionally intense dialog with profanity because it reflects what we hear in the real world. I however find that relationship to be one directional. The use of a profanity doesn't imply any kind of emotion in of itself because of how prevalent flippant usage of profanity is.
I'm aware that is a personal perspective and I may not be in the majority with these views.