I haven't read the article yet [if ever...]...
but it might be in context to remind ourselves that in fairly recent years
the B'n'P actively appropriated British Trad folk music for their own nefarious purposes...

.. and even without that political party's grubby fingers grabbing our music,
the lefty 'bias' of UK folk has always been counter-balanced
by a perhaps even more prevalent 'bias' of very conservative jingoistic folkies...