Richard Pryor would probably cuss at you, but he was funny even without the bad language - I mean I think he would have been anyway.  I don't think I ever heard him not use "bad words".

I generally agree with you and the letter writer in this case though. There's no call to use such language - especially not in the workplace or other "professional" settings.

A number of years ago I noticed that I had two modes of speaking - one "professional" in which I never said anything that would be censored on broadcast TV and one where I really didn't care what I said and in some cases the more offensive it sounded the more I liked what I said.

I felt it added emphasis - I don't think it indicated honesty at all. It indicated how strongly I felt, but if every other word that comes out of your mouth is a curse word those words lose their strength and meaning.

I rarely curse now, but when I do you should know I mean it.  And it's a good bet I may be angry too. It has nothing to do with honesty.