Jim said "Your man-in-the-street definition doesn't fit as a definition because it has no consensus"

That was the point I was making earlier - that this meaning cannot be defined objectively, in the way that you would prefer to use it. Talk of a 'definition' is meaningless. Nevertheless there is a broad consensus. What you cannot do is draw a line between this folk and a different genre - but neither can you for any other genre of music.

The definition you insist upon - which I entirely accept for what it is - is only of interest to enthusiasts and academics who wish to make a distinction between some songs and others (I'm not belittling the importance of that distincton, but for many people who just enjoy listening to music it is an irrelevance). It is not what the word means in common usage. If you want to fight that battle, you're about 50 years too late.

If I recall correctly, you are a retired electrician - have I got that right? I am sure there are many technical terms in your former profession which the general public uses in a broader or even incorrect sense - I know there are in mine. This is no different. 'Folk' has a technical meaning for one set of users and a general meaning for others. Once you acknowledge that you can determine the meaning from context, or use another term, such as 'traditional folk', when you want to be more precise.

"The definition has in no way changed - it has largely been totally abandoned by the clubs."

You keep saying this, but on what evidence? The experience of most people here is different. You seem to have been exceptionally unlucky in the clubs you have visited recently. It may apply to some clubs, but then it always did. The balance of music I hear today isn't a lot different from 40 years ago. I see a lot of young performers who are very committed to traditional music. Again, this battle was lost 50 years ago.