Jim, I didn't say that "folk song" no longer means "traditional song", but it no longer means only that, at least not in general usage.

The examples of traditional songs you mention are correctly labelled "folk songs", both under the general and 1954 definitions. However "folk song" now includes other things, unless you are explicitly working under 1954.

All traditional songs are folk songs. Not all folk songs,as the term is generally used, are traditional songs.

I agree that a performance of Beatles songs doesn't qualify as folk under any definition, but folk clubs aren't academic institutions, and if they want to put something like that on (presumably as a one-off) that's a matter for them and their audience. But if that sort of thing becomes the club's staple, then the name "folk club" would become inappropriate (and would probably put off the target audience for that music).

You seem to want the world at large to use the specific 1954 definition, but the term isn't even limited to that sense on this forum of enthusiasts. Language is defined by its usage, not what we would like it to be.

I understand your frustration at the way the term in general usage has largely lost all meaning, but it's too widely established to change now.