I say 'singers', I include players as well. I have come across some places, more than I would like, where aiming to sing or play better than you did the week before carries a sort of unpleasant stigma, like a contagious disease. Performing badly is more approved of than performing well. As long as you've tried, that's all that matters. Yes, of course there's room for that when the young or inexperienced give it a try. But there does seem to be a view in some places that if you practise between performances, with the express intention of improving, you're somehow not one of us. It somehow denies the true nature of folk music.