I always find excessive profanity (or pseudo-profanity or general negativity) annoying. I mean, why do we use profanity? To express negative feelings. Excess profanity = excess negativity (in my head) = depressing. To me it would detract from the game. End of opinion. 
While I get what you're saying, I'll have to disagree to some extent. Profanities just in sake of profanities can feel a bit stale or childish, But used in the right way, it can add realism to dialogues and writing in general. Most people swear from time to time. Sometimes unintentionally, and sometimes small everyday words injected into sentences. And even though swearing don't say much about a character, it can emphasize some minor quirks and tells us a bit about the attitude and background of the person, at least.
On the subject of negativity, I have to disagree as well, in the way that there is a huge gap between fiction and real life. I, for once, enjoyed Lord of the Rings, but I wouldn't like to be in that same situation as the characters in the book. In the same way, I can feel attached to certain characters in different fictions, but I wouldn't like them at all in real life.
I were going somewhere with this post, but I lost track somewhere. I agree with you to some extent, but in many cases, not so much. Note that I'm not trying to convert you, I just felt the need to express my feelings on the matter
