"the term 'folk' in the definition is consistent with its use in folklore, folk dance, etc." MM

Actually, the study of folklore draws upon an array of critical techniques such as narrative theory, ideology, semiotics (and many others) none of which undermine the collection of lore and myth. By comparison folk music debate is stuck in the anthropological model of '54 you suggest. It's a brittle and defensive approach which leads to the antagonism seen here, a 'warring discourse' if you like full of personality cults and ego.