"exhort everyone to bloody well get out there and do it, as performer, accompanist, dancer, organiser"   Good idea. But some people wouldn't allow it unless you pass their exam first.

As for singing folk at open mics, well, cast your pearls if you wish, but open mics are for allowing people to stand up in front of a mic, which they want to do because that's what pop idols do. Otherwise there wouldn't be mics.