Your example is no different than demanding auto companies design every car to each individuals size, driving style, taste in body style, number of cylinders, HP, .........
There are more than a few people who spend millions on autos, but that doesn't mean we all do. And if you knew anything about macroeconomics, you would understand that the cost of doing business would be (and is) cost prohibitive. It doesn't matter if "High end [cars] can already cost tens if not hundreds of thousands of dollars. So there is plenty of money already going into the pockets of the companies." That money does not cover the cost of providing luxury cars to every car owner. And unless you live in a different world than the rest of us, a very few percent (yet still many thousands of people) can afford what would be a break even price for the company to make individual speakers for every person.
Did you ever see the movie Meet the Patents? You are like the airline customer service rep on the phone with Greg Focker:
“Yeah, you gave me the wrong suitcase. Uh-huh. Yes, it's a black Samsonite. Uh-huh. Ok, well don't you think that the Samsonite people, in some crazy scheme in order to make a profit, made more than one black suitcase?”
(on the phone)