When I was newly minted, I will admit to being so gung-ho, I would always want to ask everyone what their air level is, and flash the OK a little too often. I kind of thought that was a normal thing- like we all just swam around asking each other our air supply and occasionally looking at fish.
I think a DM told me, politely, to just worry about myself and buddy only- mentioning that DM's are in the water for a reason, and my focus should be on safely enjoying the dive with my buddy. If my buddy needed help and I was off checking someone else's air, that is not good. It was a valuable lesson to learn.
On the other hand, in Cozumel last year we had a couple with maybe 10 or so dives. They were doing great until the husband developed a pretty good primary hose leak right after the first stage. The wife freaked out, but they got into air sharing smoothly. The DM was way ahead, so I shot my SMB, and signaled for them to begin ascending. I made my way to the surface with them and the DM did come check on us. Once they got on the boat, I dropped back down and finished the dive. So, I think it is always good to keep an eye out!