Ah, caught out by "chiefly British" again. Never heard of a person being a notoriety. And so, I suppose two would be a pair of "notorieties". It's a fair cop, guv.

"If five people ask to perform then we have a decision to make. Is it so wrong to decide to put on the ones who will provide the best entertainment?"

I don't know; I'm sure it's a tough call. It's your club, you can do as you see fit.

"How does that make me the villain of the piece?"

I don't think you're "the villain of the piece". My point wasn't the songs; someone "better" there wouldn't make me not want to perform, if that's what I went for and I would be disappointed if I couldn't. And I have been on the receiving end of snobbery in various kinds of situations. This phenomenon isn't limited to music.

You have your way of doing things and you're perfectly entitled to run them the way you like. You've got your audience and your patrons and if they're happy with it, that's what counts. I don't even live in the same country, so I couldn't visit your club even if I wanted to.
I get the impression that the "folk scene" is very strong and widespread in Great Britain and people there have a good chance of finding something to their taste.

It's somewhat different here (a medium-sized university town in Germany).

What you describe doesn't really sound like my sort of thing and I think it's quite possible that I'd be one of the ones who was asked not to perform or "jumped on from a great height". Why should I expose myself to that?

Sorry for having a go at you. I wish you continued success at your club.