I don't think it's specifically the internet, Allen; I think this is something that's been going on in the recording industry since the late sixties. In those days, and before hand, of course, the recording industry was controlled (in fact, because of the numbers, NOT controlled) by an enormous number of people with different ideas - that was true to some extent even for the majors, but was particularly obvious as regards the indies, which were locally based. Even within a particular locality, and within a particular kind of music, the different entrepreneurs had quite different ideas about what was good music in their localities and fields of interest; compare PJ and Contemporary; or BN, Riverside and Prestige in jazz; or Chess and Vee-Jay for blues; or Hi and Stax for R&B.
In the late sixties and seventies, a lot of these indies were consolidated into, mostly, the majors. Insofar as they weren't closed down and milked for the oldies business, the output of the companies tended to toe the line of what the new owners wanted. This led to some uniformity. It also led to greater power to influence the markets in the hands of the majors; power which, as industrial giants, they understood well how to use. Once a market becomes controlled, it's difficult to make it uncontrolled again, though a social revolution, such as occurred in the forties, can do it. But we haven't had a social revolution since the seventies; only a technological revolution, once more in the hands of the industrial giants. So consumption of music has remained monolithically directed. Of course, many indies have been opened and closed since then, but who would argue that they have anything like the impact of the majors?
Musicians start as music consumers. Monolithic direction of consumption doesn't help creativity; doesn't help spread notions of creativity.
MG