Villan,

You're making this up as you go along, aren't you? I'm certainly not going to abandon a perfectly good definition of folk song on the basis of your guesses, feelings and vague hunches. But if you want to do so, go ahead!
If you decide to do this please remember that if the word 'folk' becomes devalued and folk song becomes just another wooly-headed type of pop music (and blows away like a puff of pink smoke) please remember that you are responsible (along with all the other 'anti-intellectual-ain't-heard-no-horse-stamp-foot-everything-I-like-is-folk-throw-tantrum' brigade).