Malcolm,
         Folk concerts normally cost money, some quite a lot of money. Sessions and other informal events are normally free.
So if you prefer the latter and want to go to gatherings of like minded people, the answer is obvious, and I think there are an increasing number of people who think like that- you are obliged to accept the weekend charges at showbiz efforts like Cambridge & Glastonbury, but why go to paying concerts when you prefer informality & can actually be part of the occasion?   
Ireland & Scotland are much better at the latter type & anyway a lot of people are on a tight budget these days.