So I'm going to sound old a hell but back in my day a concerts even for famous bands, were much, much, much cheaper even accounting for inflation and I would argue that that's a bigger driver than some nebulous crap this author is offering up about people not being taught how to act from the quoted "etiquette expert"s.

Nowadays I can kind of understand because now with paying hundreds, if not thousands of dollars, for a ticket, I wouldn't want to miss a single second of a concert if I'm paying out the nose for tickets driving more people to do whatever they need to so they don't lose their spot that they spent way too much money for thanks to monopolies and spent way too long waiting for their prime spot.