It's true this thread has drifted away from the original topic onto the usual well-worn tracks. But the reason we have this debate about "purists" comes back to the difficulty we have in defining "folk" - or more accurately getting some people to accept it.

I doubt whether they have the same issues in other genres, or at least to the same extent. OK I know of the rift in jazz between trad and bebop, but if I go to a jazz club I know broadly what to expect - the same if I go to a classical concert, or an event billed as reggae, northern soul or whatever. If I go to a folk club - some clubs anyway - I could hear almost anything.

The strangest thing is why all these people performing other than traditional folk want to squeeze inside the folk tent. Apart from brief periods, folk has been deeply unfashionable and uncool. My cynical view is that the folk scene offers them an opportunity to perfor before an often uncritical audience, and to become a big fish in a small pond.