I don't know if all the people who fail to think about the audience are 'selfish' Will, I think quite a lot of them are the sort of people who lack the kinds of social awareness and even self awareness that most people possess. Take the man at a club near me (I don't go any more) who happily announced that he hadn't played his next song for "twenty years" but the last time he had, the lady who ran that club had told him it was "very nice". I don't think he actually realised before he began that not having played the song for twenty years was likely to result in him now not being able to play it at all. That may seem amazing to most folk, but there are those odd marginalised people - who my Mum would call "a bit unfortunate" - who come to folk clubs, I think specifically because the polite welcoming ethos doesn't exclude them unlike many other social environments. I don't think they're selfish, I really think they aren't aware of the unspoken social codes that most other people take for granted.