I also think he has come back into fashion recently on account of being an influence of some of the 'new folk' (probably in these here parts I should say ''''''''new folk'''''''') artists of the Devendra Banhart persuasion.

This may or may not be a good thing of course......

For two or three years in the 60s he was something of a pioneer, but the particular shape of his pioneering was to mesh folk traditions with other genres & styles, and that is never a way to please the more traditionally minded.