"Don't get me wrong, definitions are important..."
And thereby hangs the problem, they are important - important to the survival of the genre, that is.
Musical forms can exist side-by-side with others perfectly happily, until one form shoulders out the other - as has happened with folk music.
I stopped going to folk clubs because what was being dished up in many I went to did not bear any resemblence to what I knew (as a singer, collector, researcher, reader... whatever) of (then) nearly forty years of listening, as folk music.
I now live in a one-street town in Ireland where I can attend at least three excellent sessions a week (and three not-so-good ones), listen to up to a dozen programmes of folk music per week on the radio, watch up to half a dozen television programmes on same music, and attend year round singing and music week-ends; not bad for a place where, ten years ago, the same music was being referred to contemptuously as 'diddly-di music' and if you walked into a pub with a fiddle you'd be sitting on your arse on the pavement in two seconds flat.
The reason - the musicians here didn't run round like headless chickens when someone asked them to define their music - they knew what it was and did something about it.
Try telling a classicist that 'classical' should only be "a loose framework" or a jazzman that everything a horse doesn't play is jazz, and see how far you get.
Jim Carroll