Below is a link to an 2013 article in "Stereophool" (misspelling intentional) magazine that evidentally had its seeds in a 1994 article on the slow death of High-End audio. Reading the reader comments below the article gives a good insight on how the brick and mortar high end shops have slowly declined over the past 20 years or so for a number of reasons. Three possible reasons are below and there are others ..
1. The gear that high end shops carried was really overpriced. Why should I buy it new when I can go on Audiogon/ Ebay and get a mint used piece in proper working order for maybe 50 to 60% of the list price ?
2. The rise of internet based businesses. There are many internet based companies out there that sell high quality audio gear at reasonable prices.
3. The down turn in the world economy in 2006 - 2008 have caused the average audiophiles to have less disposable income and to turn to more "higher value for the buck" audio gear.
Check the link below and if you have any comments post them in this thread ...
R.I.P. High-End Audio article in Stereophile