I see this "pic at shows" thing like the Napster thing, something new that comes along and takes some time to get adjusted to. Metallica sued Napster, Iron Maiden in 2003 when premiering a new song at shows said "Record it, upload it, do whatever you want with it, we don't care, just buy the album when it comes out if you like the song".
Same things with pics, I respect the band's desire in this sense, and I get their frustration "Are you even listening to the song and enjoying yourself or are you just showing off to your friends at home that you're at a show???", but there are also people like me who are amateur photographers and like to have decent memories of a show. Hell, it's no comparison to big bands like DT, but the little I've did as a photographer in the underground scene around me was thanks to pics taken and posted online and some bands eventually granting me to be in the photo pit at an outdoor gig or whatever.
As a lover of photography I also find ironic how in some places they don't want cameras, but accept phones. I went in Switzerland to see Wardruna and my camera was confiscated at the door. But people used cellphones, and the best ones have an absolutely great camera, and no one seemed to care.
I saw it reported here, probably, that James once at a show said something like "Hey, come on, I don't say 'Don't take pics', take three or four, but then enjoy the show and live in the moment". Like Maiden back in the 2003 this could be the way to go, acknowledge that the audience will do whatever they want, but politely make them think "Do you really need to take 700 pics of the show all the time???"