@dpop Totally agree, drives me nuts!. Really crazy how audience behavior has changed over the decades. This as it pertained to rock concerts and personal experience. Early 70's audiences rather reverential in that they were totally engaged with performance, quiet and even sitting in their seats with exception of encores. This behavior was common at indoor venues, outdoor or festival audiences far more rowdy. Over time audience participation increased, I really think Peter Frampton's Come Alive release exacerbated the audience as participant in performance thing, Springsteen certainly added to it.
As far as recent sound quality at shows, I've seen Railroad Earth, Beach House and War On Drugs at same local venue, Railroad Earth best of three. This theatre has pretty bad room acoustics and house sound reinforcement guys have no idea, louder and louder better for them. Railroad Earth saved by being more acoustic based band. Saw Kraftwerk recently at another venue, much better room acoustics here and house sound reinforcement guys controlled volume much better.
The problem largely lies with house sound guys and equipment, you learn some venues never produce good sound. In order to get good sound, very high likelihood band has to have their own sound guys, equipment, and how many bands have the resources or even care about good sound quality to do that.