my understanding of it is this
paid gigs should be advertised as trad music with dick miles or jim bainbridge or a n other, imo sessions are unpaid, doesnt mean the music is any better or worse.
Jim, your gigs were always welcoming, but not everyone is like you, particularly when the group are amplified and travelling musicians are not , immediately there is a them and us situation, and some of these trad groups are quite happy not to have anyone join in with them.