The British have a tradition of forming clubs. Whether this is for folk music or steam railway enthusiasts or plastic model aeroplanes or knitting or book reading or whatever. There were a lot of folk music clubs in the 60s/70s when folk music was genuinely widely popular because it overlapped with popular music. There are fewer nowadays because it doesn't, and it is often thought "untrendy". There are fewer shops selling plastic model aircraft too, partly for similar reasons.
But model clubs still exist, even thrive. Folk clubs still exist, even thrive. Music clubs differ from most, however. No-one is going to go regularly to a knitting circle unless they knit. In music clubs, not everyone who attends is a performer, or necessarily wants to be a performer, or play an instrument, or sing themselves. They just like folk music, and the club is the only place where they can regularly go and hear the music, and meet with fellow enthusiasts. Concerts are not social, and are more expensive. Local sessions and singarounds just do not fill this social gap. The internet may be weakening this dependence on the club, with music stations and social networks such as Mudcat, but has a long way to go. The growth of sessions may be weakening the clubs by drawing away talent, but they are basically restricted to performers and cannot play the same role. The number of festivals may be weakening the clubs, as the more enthusiastic can travel to different festivals each weekend, but that is limited to the socially and/or financially mobile.
Until folk music becomes restricted to performers talking only to themselves, there will be a place for clubs. The exact format may well differ from the classic 1970s style. Locally there are as many clubs as there were 30 years ago, but I see much less emphasis on guest performers. The role of the club in encouraging and supporting professionals clearly has shrunk. I don't see the answer in better publicity: that might well help a few marginal clubs but can only have small and local effects. If you want a return to sufficient healthy folk clubs to provide good wages for large numbers of professional artists, the answer lies in folk music becoming popular again.
And that can only come from the performers. If professionals want to make more money they must make more popular music. If folk music doesn't sell, then by all means play in theme pubs, the music people want. If you can bend their tastes in the direction of folk, so much the better. If that means melding the more traditional folk with more popular music forms, so much the better. It was done in the 60s. People didn't flock to folk clubs because they took a sudden liking to purist traditional folk. They went because protest folk was popular with the young, and folk rock was popular, and there were artists who fed off this popularity.
Those who attend modern folk clubs are rarely hard core traditionalists. They are people who heard Dylan and Steeleye Span when they were young, and grew to appreciate the roots of the songs those artists used. We've had a generation without (or nearly without) such popular support: where "folk" became identified with comedians such as Capstick, Carrot and Connolly rather than the music. We've had a generation where political protest was marginalised. There are signs that the scene is improving - let's hope so. But it isn't going to expand again without popular support. More of the same, however good, just isn't going to do it.
Regardless, the clubs will continue: smaller maybe, cheaper maybe, but they aren't going to stop as long as people like gathering together to hear folk music. Not to play, not to sing, but simply to hear.