This is the nearest to a half decent discussion on the meaning of "folk song" that anybody has even been able to manage

I'm not very interested in that, and it's quite irrelevant to the the original poster's point - which Steve Shaw picked up on a few messages back: a lot of what happens in folk clubs and singarounds is shite. This has nothing to do with whether it's genuinely traditional or not. It's to do with whether it's shite or not. You can decide whether or not to be shite no matter if you're doing a Child ballad or something you wrote last week.