Why Are Bad Words Bad?

So, apparently I am the Lenny Bruce of the Central Pennsylvania Planners Association. Certified planners -- city planners, zoning officials, land use managers -- have a mandated requirement for continuing education to remain in good standing and they must have an hour and a half of that continuing ed relate to ethics. Last year, the state-wide gathering was in Gettysburg and they asked if I could lead the ethics session. I agreed and it went well.

So, a few months ago I get an invite to speak again to the central regional group in Harrisburg. I agreed and went up yesterday and did my schtick. Afterward, I'm chatting with some of the planners who are on the organizing committee and they tell me that there was controversy around the invitation. The committee was split down the middle between those who found my stand-up comedian style refreshing given what these continuing ed seminars tend to be and those who were set against having me back because apparently last time I used a couple of four letter words during my lecture and they thought that some one who used bad words was not someone who had the credibility to talk about ethics. Of course, I use them as "flavoring particles" to shock, surprise, or get a laugh when I feel my audience slipping away, so they serve a purpose for me in the classroom. It is not gratuitous. But, needless to say, I am still chuckling about it.

And, of course, is re-raises the question, what is the meaning of "bad" in bad words? What makes profanity problematic? Is it a moral problem? Is it mere social etiquette? Are there contexts where it goes from a faux-pas to an unethical act? Is it a sign of disrespect? What is the nature of their naughtiness?