Sharp was a member of the Fabian society, a left wing group, that hardly fits with the description of Imperialistic paternalism, Rudyard Kipling is amore fitting character for that description

Left-wing thinking is just as patronising to the lower classes as Right Wing thinking; both see them in terms of being faceless compliant masses rather than the hot beds of individual radical thinking and eccentricity that they actually are. The corpus of Tradition Singers is abundant evidence of this fact, likewise that of the other arts, sciences, musics etc. The Bourgeouis Revivalists (whatever their political stripe) were very careful in what aspects of working-class culture were to be harvested as being Folk and what aspects were not. This was not simply a matter of idiom either. Even latter day lefties like Ewan MacColl had very clear ideas as to what constituted Folk Culture and what didn't, despite the fact that Culture Is as Culture Does, and doesn't need the poscriptions of Eavan MacColl or David Franks to tell it what it ought to be singing and why. I'd agree with you on Kipling though - he makes this abundantly clear in his poetry, not least in The Land which is a paean to the very right-wing notion of the passive continuity of traditional working class servility to the fuedal masters. Always strikes me as odd that many sing it as a Socialist polemic - as if Kipling would have ever written such a thing!

Saying that 'folk' means 'in the folk idiom' is like saying that a 'cat' means 'a member of the cat family'

Post-revival, Folk is just a matter of Folk Idiom (which covers a fair few bases I'd say) just as cat is a matter of felinity first and mammality second. Defining the specifics of those bases is another issue, of course, like the Popular Song & Ballad Idioms of the Oral Traditions of the last 300 years or so. Calling them Folk Songs out of pragmatic convenience is one thing, but defining them as Folk (and all that implies) is quite another.