I have managed to make my peace with the way people fling the term "folk" around. If pressed for my definition I would say something very close to the 54 description but, if asked to describe a particular group's music, I would use the term "folk" or some variant simply to
give people an idea of what to expect.
Similarly, again if pressed, I have a pretty definite idea of what I think constitutes a sea chantey but mostly keep quiet about it unless
involved in a serious discussion about the form.
I always enjoy the discussions on Mudcat about this, not in search of a final definition, but because there are so many thoughtful responses to the question from people whose opinions I have come to value through
reading their posts on a variety of topics.