Dealers and exaggerated treble

I've been thinking about some negative experiences I've had at dealers over the past few years. I don't mean the dealer's were unpleasant, they were not. I mean that I heard bad sound.

In a lot of those cases, the treble was exaggerated, or harsh to me.

I'm wondering, have you ever heard really bad treble at a dealer, but then you hear the speakers elsewhere and they seem fine?
I’ve been to dealer showrooms where the room itself is a terrible place to listen. One I recently visited had a dozen systems placed around the main listening room. It was also littered with other equipment in racks and on shelves with accessories and junk piled everywhere. Nothing sounded good. I don’t think the staff there knows much about audio or how to set up a system. But there is no competition anywhere near them and that’s why they do well. The good news is anything you buy there has to sound better when you get it home. 
Yes, I've definitely experienced the "salespeople have no idea what they are doing" syndrome as well.

At least it is benign of intention.

Unfortunately,  if you don't know much or are just getting into the hobby this can happen.  Otherwise, there's no excuse for a bad demo - it's on you for not asserting yourself.  It doesn't matter what the dealer thinks sounds good - do your homework and come prepared.  I once hauled PCs on a 10 hour flight to make sure the demo was as useful as possible.  If the dealer is too lazy to listen to your requests find another one.
i immediately heard and pointed out that the speakers were wired out of phase. He then corrected the mistake. I was shocked at how this could have happened. Either deliberate, or a mistake. Either way its deplorable.
It’s "deplorable" to make a mistake?
Have you ever made a mistake?
To err is human.
yes deplorable to set up a pair of high end speakers without listening to them and positioning them and noticing that theyre out of phase. The guy didnt even notice until I told him. Either that or it was deliberate