"it all sounds the same"

I think is common enough. As a player, I don't get how say a reel followed by a jig, then a hornpipe, can feel the same but, sadly, it seems to work that way for some. I must confess I have a similar problem with the fast bluegrass tunes - a couple sound blindingly brilliant but then I can get tired.

"they sit around drinking and talking until 1/2 hour before closing time, then we can't get them to leave"

I'm not aware of that one sessions I've been to/go to. Some nights may have gaps of talking, esp if a night is thin on players, but usually people want to play the night through (although I will concede many could play on another hr or so given the chance). Currently, the ones I go to are on a 10:30 finish anyway.

"it doesn't bring anyone in"

I think some do, some don't but mostly people accept the music. I've been in pubs where you can feel some hostility from locals and others where you feel really welcome and do see people come because of the music. I have experienced these differences with the same groups of players.

"some of the musicians are clearly very talented others, not"

I'm not sure I've particularly picked that up as a listener. As a player, I'm very much aware that some like me get by and others are exceptionally (and I've for example come across 2 Irish champions in sessions I've been to) able but I think what I hear when I'm out of the table listening is the combined efforts of all.

There is incidentally, one session I go to less often now as I've been unable to keep up with the change of repertoire (you can get not one repeat in say 3 weeks and I'm mostly "old standards") and am limited in how often I get out and opt for one I can join in playing more.

I can appreciate the music even if I decide to go there just as a listener. I doubt many of the other customers really do and I think it's a shame but, to some degree, their loss (by that I mean, of course you are delighted if you pick up for example toes tapping round a table, etc.).

Sometimes I think evenings could be made more popular perhaps for example by throwing in the odd Wild Rover or Fields of Athenrye, etc. but that's not what the nights are about or what brings the pleasure to the musicians.