Here's a rather tentative notion from someone who has not really kept up with the literature on folk song and folk song origins.

I'm an amateur botanist living in Manchester. In this region, in the late 18th/early 19th century, there existed something which has been labelled the 'Artisan Naturalist Movement': a loose association of working men (haven't come across any women yet) who shared a common interest in nature - particularly botany. Many local communities had a botanical society. These societies had regular meetings, usually in the upstairs rooms of pubs and at these meetings plant specimens, submitted by the membership, were identified and discussed. Many of the key figures in this movement have been identified and we know something of their lives and occupations; hence John Horsefield was a hand-loom weaver, Richard Buxton was shoe-maker, George Crozier was a blacksmith, James Crowther was a porter on the canals etc., etc.

I suspect that it's significant that as the 19th century progressed, the movement declined. Until the factory system took hold men, such as those I have listed, were self-employed and independent but their successors were reduced to 'mere wage slaves' by that system. Afterwards such men had much less time and energy (and money?) for such relatively esoteric pursuits. I note that John Horsefield was a witness to the 'Peterloo Massacre', in central Manchester, in 1819. This was a political meeting, at which hand-loom weavers, like John, protested against the loss of their livelihoods and independence; the meeting was savagely broken up by the local militia.

Were there such people as 'Artisan Song-makers', I wonder and did industrialisation mark a watershed for them too? Perhaps this is all, in a sense, just a statement of the 'bleeding obvious'?