"those who decide that they are good enough but others are not."

Richard, I find it hard to believe that anyone, including you, would fancy regularly attending a session where contributors don't practice their pieces before performing them. The "I haven't played this for twenty years" quote was from life. Last I heard, that session needed more people..

I don't take issue with people running sessions in any way they want to, it's a free world, but if there are a small core of regulars who can't be jogged into at least practicing their pieces first, then those sessions will obviously die because they will be the only people who do attend. And that is a loss for everyone, including those who have devoted their time and effort to establish the session in the first place.