Great question, and I'm not sure why either. I have observed people at my house as they look at and/or listen to my system. I think that most people simply don't care or don't think there is an audible difference between high end and mass market. There are some that can tell the difference, but are intimidated by the complexity or cost. Some (often women) don't want to deal with the integrating something like this into their decor. In the 20 years I've been into the hobby, there's only been one person out of so many that came to my house and was impressed enough by my sound to buy an audiophile grade system of their own.
Why Don't More People Love Audio?
Can anyone explain why high end audio seems to be forever stuck as a cottage industry? Why do my rich friends who absolutely have to have the BEST of everything and wouldn't be caught dead without expensive clothes, watch, car, home, furniture etc. settle for cheap mass produced components stuck away in a closet somewhere? I can hardly afford to go out to dinner, but I wouldn't dream of spending any less on audio or music.