Ron G.
Contributor
Ron G. I am not sure why you have the impression you have.
Keith, as I said, it's only an impression.
I've tried to get an sense of the groups based on online photos and comments. I'd agree with you that they seem to be 30's - 50's (I'm 63, but that's close enough).
I've been on several dive trips, some as a single, some with a LDS group and a couple with my wife. The trips have been to Coz, Roatan, and a couple liveaboards. On all those trips, the large majority of divers seemed to have dinner, then disappear to their rooms....mostly to get to bed early.
The trip photos I've seen seem to represent a much livelier crowd. (In fact, I can't remember seeing a single photo of tired divers heading off to bed after dinner. Go figure.

Another SB'er sent me a PM echoing what you've said, so I'm going to re-think it. (Right now, I'm looking hard a a great deal offered by Blue Angel in Coz. If my wife won't go, I may go alone.)
Thanks for the comments.
Ron