In my opinion, people should not spend that much on speakers, what's the difference between a $10,000 pair of speakers vs. a $20,000 pair? At 10K I should be able to purchase a great pair of speakers. There should be no need to spend more, if not, I have wasted my money.
That said, I believe people make poor purchases, not because it makes them happy but due to marketing. Saying that superfluous, useless features that drive up the price of a product are purchased because they make you happy is a bit of a cop-out.
That Denon unit is priced at $6,500 and it doesn't have Dirac Live, which most people in this forum have opined is a superior room correct software to Audyssey. That would be a useful feature for a premium-price product. However, they want to give you useless stuff like 15 channels, when small rooms don't even need it.