My guess is that these things ebb and flow. The arrival of a new genre or subgenre can spark a lot of interest and passion, and sales (think grunge and alternat

My guess is that these things ebb and flow. The arrival of a new genre or subgenre can spark a lot of interest and passion, and sales (think grunge and alternative). A long period of stagnation can cause sales to decline (think mainstream rock in the late 90s - early 00s). Of course, this is all anecdotal opinion, so take it with a grain of salt.