I think it is a generational thing.   The "folk revival" crowd developed their taste in music and created their own styles when older generations were siding up to pop music, jazz and other more commercially accessible forms.    Now that the folk revival crowd are entering their latter years, they seem to have the same sort of resentment for younger generations who are embracing music in their own style.    Perhaps it is a jealousy of realizing that their own rebellious youth is a distant memory and by looking down their nose at younger styles, they somehow recapture their own youthful arrogance.   Too bad it is at the expense of hearing some unique and exciting music. The cowebs are shaking off revealing a brillance once again. Perhaps if it is put down it will go away and they can embrace their memories again.