I was intrigued to start selling on this or atleast looking at it, until I read that email, very sneaky! I dont want to do business with these people. Especially looking at some replies in this thread, makes it look like they were written by people who are working for shophandmade ......suspicious!
I dont think it's generational, there are always people that say and laugh at flamboyant language and gestures. Its just in their personality, they dont take the little things seriously.
However I do find people in my age range want to spend the percentage of their hard earned cash on things straight away as they have no kids nor mortgage - and they arent looking for matching doilies or sensible, practical things.
Not to be rude but it doesnt matter about the person in the booth next door, theyre in their own booth how does it affect them? Youre not shouting those words at them, and if people dont like the profanities then wont they just walk on by to the next booth anyway? I do think you should take note of what the market/show is and think carefully about what you present. Some people and organisers might not want to create the "wrong" look or feel to their event.
You can be a professional artist and craftswoman and still use colourful language, it doesnt bring you up or down in skill or craft. Possibly maturity, but hey I never said I was mature. :-)