Goes back to the problem of Breakin, most very expensive amplifiers are not broken in when you buy them. It takes a while. So what your hearing at the dealer if you're lucky enough for him to have a broken in higher-end amplifier that you have an interest in comes nowhere close to what it will sound like at your home. Most purchases are on faith. Gear looks pretty and expensive so I like it and I'll buy it.
Additionally if you have a large net worth spending 40 to $50,000 is all about optics.
I suspect most of these people buying expensive gear have no idea what it is. They trust dealers and they don't install themselves. It's too damn heavy. And then they turn it on and it sounds nice. And then they go to their other homes and may not even listen to this new system they bought for quite a while. It's just a piece of furniture in the room probably a lot cheaper than the other furniture they have.
It's like a trophy wife, you buy the gear because it makes you feel good and you want other people to see it. And what else are these people gonna spend their money on. Having a lot of money it's not what it's cracked up to be.