The concept of "Folk" has consistently been exclusionary and usually evaluative in a positive way.

As in
"folk" good.
"non-folk" bad, or less valuable, less worthy, etc.

I know this is hard to believe if you've heard the term "folk music" being used pejoratively. That's a fairly recent phenom.

The history of the concept is quite interesting.

It has never been value-neutral.

That said, it's never surprising when a definition of "folk" excludes large swaths of musical terrain.

In the definition above note the implicit contrast between
"folk" and "popular." Now that's a real can of worms.

Russ (permanent GUEST)