I met two professional musicians one evening at a small venue. Chris Smither was the nicest guy you'd ever want to meet and he even joked about his "technique" when we spoke. Rory Block was on the other end of the space-time continuum. Rude to Chris when they played together, rude to the people at the venue and rude (to paying guests) at the intermission.
Clearly some people haven't read the be nice rule...