It's worth remembering that song traditions used to be gerontocracies. IE., the older you were, the higher your status within the group. Therefore, it would not have seemed at all out of place for established singers to give free and pointed criticism to younger singers.

Whereas today, Elizabeth LaPrelle and Julie Fowlis are both a lot younger and quite a bit more talented than the average Mudcatter. Maybe it behooves older folkies to give respect where it's due to younger performers?

People on the folk scene who have spent 50 years not learning how to be polite, constructive, friendly and appreciative are more of a problem for its continued viability than the occasional talentless newbie.