the smaller they become the more they seek 'purity' and the more they purge or seek to purge the impure.

Is that what's at the bottom of this? The very idea of 'purity' brings me out on hives, let alone this notion of 'authenticity' and 'correctness' that many folkies get off on. Folk (in common with every other genre) is the music of What Happens, not what Ought to Happen. My mantra for years now: let 'authenticity' be the reserve of the model railway enthusiast, who would, one hopes, at least have the nous to recognise a REAL train should ever they see one - and for the sake of our collective humanity let 'purity' be the concern of the dairymaids. In music (as in culture, as in people, as in language, as in life) Contaminants are Very Good Things - and, Glory Be, we're all post-revival now, peeps - so do what thou wilt with Unfailing Joy, Unimpeachable Sincerity and f*ck the detractors. As Stan Laurel said, life just isn't short enough... too short by far.