You can say that again! With one exception in the past year (not that we do many gigs) I can't think of any club where the audience had more than a token of younger people attending.
What I recall from nearly 50 years ago is that our local folk club was the place to go for the more radical 6th formers!... mind you the organisers were only a few years older than us, and not our parents or grandparents age. I too believe that the festival - dance venues are where the young get their dose of folk music these days if at all - I use the word 'dose' advisedly too, after all it does them good!