In North Kent we have 2 established folk clubs. One is a guest every week - with - mostly - the same floor singers. It has the advantage of very good beer. The same 50% of the audience go every week. In August it has smaller sing arounds. The other is more varied - singers nights and guests nights with a wide range of floor spots, and running sessions at local festivals.   

I think one thing the guests could do is find out and consider the type of club they are attending and revise what they do with more thought. eg If it's a join in type club then do plenty to join in with( rather than the latest new 6 songs from my CD). If its a listening club then change appropriately. Also, they could have the courtesy to listen to the floor spots, with the proviso they are tuned up and ready to go when asked.
FloraG.