"I doubt if it's anything to do with the legendary curmudgeons cited on the other thread. They impinge on the imagination of the populace at large not one iota."

Dunno about that either. I reckon if you asked the average chap or chapess to define what a traditional folk music enthusiast was like, 'grumpy' would score highly. 'Exclusive' and 'hairy' would follow close by.
Modern sensibilities often have an acoustic shaped hole to be filled and folk fits as well as anything. See a Bellowhead gig for the number of young, conventional people listening to English traditional music with very little in the way of song introductions to see how accessible it can be. If the population at large aren't listening it's not the fault of the music, so where does the blame lie?