Generally the shows I go to, and play, the band's backline is a significant part of the volume. Mostly they're at smaller local venues.I wonder, though, how much an audience member can tell about how loud the band onstage actually is, when they are being pummeled by the PA system. As an example, I went with some friends to see Steel Panther when they came through St. Louis back in December. We were pretty near the rear center of the pit area, standing, so maybe 25-30' back from the stage, and the band seemed crushingly loud. It was fun at first but about 3/4 of the way through I'd had enough, and was tolerating it rather than enjoying it for the remainder. In particular, Lexxi's makeup mirror I mean bass guitar, was flapping my pants and blowing saliva out of my mouth if I didin't keep my lips clamped shut. My eardrums were both blown into the center of my head...and I saw no onstage bass amps. Satchel's guitar appeared to be going through a single EVH head and a 4 x 12 cab. So, I doubt the onstage SPL was so bad, given the size of the room.
And back in the 90s I saw Pavement one time, and it was a pretty loud show. This was Crooked Rain, Crooked Rain-era, so not a whole bunch of indie distorted noise going on...more in the odd-tuned cleanish sour twang phase of the band. But the club had a big PA with a bunch of subs. I think (Cor-Crane Secret era) Polvo opened that show, and they were pretty damn loud out front too.
High SPL isn't "bad" unless as a band you haven't figured out how to make your sounds go together at high SPL.