It was not the chattering classes who preserved and evolved folk music. It was ordinary people

Precisely what I've been saying, although I'd take issue with the term ordinary people. As I said elsewhere, in my experience of traditional songs & the singers thereof there is nothing in the least bit ordinary about these people. However, it was the Chattering Classes who hatched the concept of Folk Song and its attendant Holy Cows (The 1954 Definition, The Folk Process etc.) in an attempt to prove that this music was the product of the collectivity of a ill-educated impoverished class in which individual creativity was impossible largely on account of that ill-education & impoverishment. To go back to E.P.Thomson: Folklore, in England, is largely a literary record of 18th and 19th century survivals recorded by parsons and by genteel antiquarians regarding them across a gulf of class condescension. The same is true of Folk Song, and remains so to this day, as posts such as yours demonstrate. Meanwhile, the working-classes continue to make great music & sing great songs, just as they always have done. The self-same Tradition that gave us the so-called Folk Songs is alive and well, just the nature of those songs are different simply in terms of genre. Nothing has died, it has only changed, as society has changed, and the experiences of the people with it.   

not by design, not in specified combination, but by the aggregate effect of their individual decisions and errors.

Yes by design; yes in specified combination, yes by individual decision, and maybe even by error too - after all, mistakes often lead to the most wondrous discoveries - but ultimately, by the self-same individual musical mastery that was as much part of working-class culture down the ages as it is today.

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A private note for Richard's eyes only:

I'm a bit worried by the overall tenor of your posts here, dear boy. Like WAV you justify your outrage with a pointless precis of an wholly irrelevant CV then proceed to tell us how little you know, or even care about for the subject in hand - and all couched with a hostility that is as wearying as it is entirely misplaced. If you've got anything to add here, then by all means do so - but please leave the aggression & insults out of it. I suggest you get together with Folkiedave and find a suitable anger management counsellor to sort out your - er - little problem.