One of the first things I learned in business school was the old saying, "You can eliminate the middleman but you can't eliminate the middleman's function". As a former audio retailer myself I was very much aware of the function we provided: bringing the goods to the customer so he could actually see and hear them before purchase, education as to what goes into a good sound system (and how to do it all within your chosen budget), and a comfortable place to relax and enjoy before you buy. Then, of course, we had to offer the goods at a competitive price.
Over the years, many of these functions have been shifted elsewhere. The internet can give you lots of information about the goods and you can often buy direct from the mfg. The education function is provided by reviews and, particularly, by "objective" hobbyists on this and other forums. The listening is a problem but the common 30 day trial goes a long way to offset that.
All that is left for the quality retailer to provide is the opportunity for comparative listening and a fun place to relax and hang out. When so many of the middleman's functions have been picked up by other channels, the retailer is too often left with the just hang out crowd and not enough of them spend enough money to keep very many of these retailers in business.
It is no one's "fault". It is just the way it is.