Tom:
"I'm beginning to suspect that you don't read posts very carefully before replying."
Sorry - I'm doing this on the hoof at present; if I have misread your point, I apologise.
As I see it, by giving a title to what you do - 'folk', 'classical', 'jazz'...., is, as far as I can see, entering into a commitment to provide a specific type of music - that is the basis on which you draw in your audience (or sell a certain flavour of soup, or whatever business you happen to be involved in).
As far as folk music is concerned that has worked fairly well up to comparatively recently.
While it is true that circumstances or added information can alter our understanding of what we do so the definition evolves, the prevailing situation is that clubs now honour no commitment to provide any specific type of music, thereby depriving any audience member to choose the type of music they wish to listen to - they/you have ripped the label off the soup tin!
As far as any public misconception surrounding the term folk (in my experience, not a term in general currency) - language is based on concensus, on which communication is dependent - take that away and we cease to talk to each other, the existing state of affairs in the revival.
As far as 'sloppy journalists' and 'Britain's Got Talent', you would no more give these people the right to misuse and manipulate our language than you would give Heinz the right to call their tomato soup Mulligatawny - or would you?
Jim Carroll