I shouldn't let those ballroom sheep lull me to sleep, Callie. You seem to be making several valid points.

You friend was treated shabbily. Beneath an appearance of kindness and politeness, folk venues often have an underlying competitiveness. The older dogs have marked their territory and don't want to give an inch. Younger folks are poorly represented and not always welcome as folks who can contribute to folk music. You practise a lot, learn interesting material and can perform it better than most of the folks at the get togethers, but you're efforts are under appreciated by an audience of competative musicians who would rather perform than listen to someone else.