Folk songs had no competition back in those days. Each successive new style or genre attracts it's own adherents. This in turn thins the audience for other forms.
When will we learn to accept the fact that we are a minority interest?
Enjoy it, don't try to analyse it.
In the same way that pornographic pictures have gone from just pictures of naked people, to gynaecological text books. So some folk music adherents are in danger of analysing themselves up their own arseholes!
Both of which seem to me to destroy the enjoyment.

The thought occurs to me, that as pornography has gone from hirsuite to baby bald, will folk musicians evolve in a similar fashion?