I think for younger players its often hard to find a critical mass of folk interested other musos to form a band - folk clubs are not as plentiful as in the past and even irish sessions in spit and saw dust pubs seem to all be professional musicians paid for their attendance these days.
I'm afraid that that is very true. When I was doing my "apprenticeship" round the folk clubs in Manchester and West Yorkshire there was a choice of about eight folk clubs every night that you could go to. Unfortunately they mostly charged 40p ("Do you think we can charge £2.50 for Martin Carthy?") to get in. This does not instil the passing trade with any confidence. "If it's cheaper than the price of a pint, then it probably isn't worth it." This in my opinion is one of the reasons why a lot of folk clubs died the death and only the great from that period are still working.
Let's not forget also that pop and rock, even (gasp!) prog music were going through a particularly strong phase back then too. The 70s was a decade of amazingly open-mindedness about music. Along came disco and punk, both necessary and vital, but unfortunately the record companies moved in and homogenised everything. People took sides, and that was the end of Britain leading the way.
The 80s had some good stuff but so much dross. And where did the young folk people play then? Did they have to wear strange clothes and makeup? I don't know. was either very stoned or working very hard.
I think maybe that sessions had died out in general or become the reserve of the older traditional player in most pubs by the late sixties and it was the young turks, the likes of Planxty, Stivell, Swarb, etc, that got some of us younger people involved again. Mike Harding in particular I always thought of as a catalyst in the Manchester sessions.
Later on when the number of folk clubs had dwindled and I still found myself the youngest in the room at 44, I remember talking to a colleague about this very thing and he said, "So what happens in twenty years time? There'll be no-one to play to coz they'll all be dead."
I think it's great that there are some great young players coming though now, Miranda Sykes, Angus Lyon, Harriett Bartlett, Gwenan Gibbard, Joe Wright, etc We all have to support them if any of us believe in the future of the past. Why can't we get the young people to like it too? Just needs someone with the media free rein of the likes of a Simon CowHell to manufacture such a band and wouldn't that be great? No, but it might get the kids interested in the heritage of the tradition.
Blah blah don't listen to me, I'm a rocker, but very grateful for my apprenticeship in the folkclubs of the 70s (Old f**t)...