As someone who served and explained fine dining prix fixe for many, many years you have had the rare experience where it is the younger folks with no respect.
I cannot think of a single time I had issues with guests under 40 in those meals. I also can't remember a single night where I didn't have at least one table of 40+'s talk constantly, complain about the food, ask me if I'm sure I knew what I was doing (Pretty sure I did since I made the food you're eating), or just generally disrespect the members of the staff and the time and effort going into it.
Now I'll have to try the chefs table to see if I can get a group of these rogue "under 36-year-olds" and find out where they've been all my life.