I think it's simply an issue of camera prices coming down to where just about any diver can afford them. As others have stated, look at the behavior of professional photographers. Some are boy scouts, I'm sure.. I've seen at least two professionals laying all over marine life to get a shot (and I have well under 200 logged dives).
When you dove before, you didn't see this because not every other diver had the bankroll to buy and use underwater photo/video equipment.
Go-pro knockoffs can be had for well under $100 with everything you need.
I sure agree with you here. The worst "offenders" I have encountered have been people who have the biggest and most expensive systems. You could see that the worst ones really had no idea how to get a good shot anyway. They seemed to think that splashing out on this huge expensive system gave them some kind of priority over everyone else. A big system does not a professional photographer make!
@MMM It is amazing how thoughtless people are with cameras in general. Trying to get a decent shot at any of the tourism events around here is frustrating to the extreme. Cameras on sticks and people using tablets as cameras seem almost impossible to avoid!