...though I still think that if you're stuck with a crap sound system you could compensate by turning it down instead of up.

Oh, I do agree. I wonder sometimes whether people can actually hear the racket they are making. In more charitable moments I presume that their ears are shot and they really cannot tell the difference between a bass line and the sound of a chainsaw on sheet metal. More often I assume that they are just fuckwits who never had any kind of aesthetic sensibility to begin with.
A similar phenomenon arises with crap bands, who obviously think "We're crap, but if we turn our amps up far too loud for both the amps and the venue, then no-one will notice."

Hope you feel less pants today.