Good points from Greg, I reckon.

Maybe folk & classical share a common problem, in that there's a perception from a lot of people that they're "not for the likes of me." As much as I love (some) classical music, this was very much the feeling I had the first time I went to the Royal Festival Hall, even though (at £6 for the cheapest seats) it was one of the cheapest nights out in London.

The "not for the likes of me" factors might be different in folk (FWIW, I think it's largely a question of image), but they're there all the same.