I've pretty much stopped going to art museums, aquariums, and other places where rare things are displayed so that people can learn about them, other than when I know I can get in at a time when there won't be school groups, party buses, tour groups marching behind flags, and the like. The flashing makes me blind, the bad behavior makes me feel older than I am, both of which I am sure I would tolerate better if I felt like the hordes were there engaging and learning. That's not what I've seen in recent years.
What I see is very equivalent to geo-caching. People go to the Louvre so that they can bounce through checking off paintings that they heard about in humanities class, or that someone told them were important. Instead of engaging, they grab a snap with their cellphone to prove that they were in front of the painting, and then navigate off to the next station. I've seen it many museums in many parts of the world, and in aquariums. In the 20 seconds spent in front of the Desired Object, 15 seconds are spent getting the image lined up in the phone's screen. The difference between seeing a work of art and Seeing a work of art is pretty striking.
Geo-caching is a wonderful sport but it's not about engaging with the destinations, it's about engaging with the motion. I used to do something similar with my nieces and nephews when they came to visit and I took them to an art museum - for kids a lot of motion is necessary so that engagement of some sort can happen here and there. I used to pick a subject - St. George and the Dragon, for example - and send them off to see how many times that subject appears in the art (and not just in the title) and they had to prove they were at each by telling me something specific about what was different about St. George or the Dragon in each of the pictures. Without that part of the game it'd just be all about rapid navigation and collection without engagement. I made sure they cached something ABOUT the image, not just its presence.
As to the flashes damaging the images - for those who may doubt, take out your trusty large flash unit, set it to full manual power, hold it two inches from your skin, and flash. Feel the IR and UV? To those who now argue the inverse square law makes flash in a museum harmless, I say you don't have a good grasp of large numbers. Yes, the flash are five feet away in the museum, but the number of flashes is in the millions if not tens of millions a year. That makes the number of energy carrying photons per square inch hitting the painting much larger than what you felt on your skin. Similar to the issue that one car in need of a tuneup can't cause a problem... but if you get a hundred million of them, now you're talking about mega-tons of environmental impact.