Couldn’t disagree with you more either. I’ve been in this hobby for about 40 years and have heard many great systems in untreated rooms. I’ve had the same living room for 30 years and have heard great, good and bad speakers having no room treatment.
I’ve had a recording engineer over to my place who pronounced my room perfectly fine, as is. Same with a high end dealer. Both have been over more than a few times.
Too many makers of "high end" gear blame the rooms on the bad sound they get yet there are other makes in the very same type of rooms getting great sound. What’s the single underlying factor in all of this? It’s the gear and not the room.
Granted, some rooms are nightmares, but I know of no one who lives/listens in a perfectly square room or a rectangle where the width and length are perfectly divisible by the same number. A great sounding speaker will still sound good in a bad room, letting you know of its potential. Not that hard to figure out.
As for going into a show of unknown quality expecting it to sound good, well you just laid bare your expectations of it supposing to sound good when it doesn’t. Sounding bad is more a matter of associated gear and cabling and people just fooling themselves.
Just try moving around some in a "bad" hotel room and you’ll hear the differences. That, or you’re tone deaf.
I’ve been to shows where a dealers set up sounded sublime and at the next show, literally sucked. Yes, the room was different but much more importantly, the surrounding gear was all different. System synergy plays a really big role in maintaining great sound. It's not plug 'n play.
All the best,
Nonoise