The Prodigy did pretty well because they presented themselves like an angry modern rock band, not some remote studio creation. You sure don't need to read music, but you probably need a reasonably proficient musical collaborator to adapt your songs into palatable form. Or a reasonably proficient computer expert who's into music programs. But I think, and some evidence bears this out, that a large percentage of Napster users use the service as a way to check out music, and go on to buy a lot of records prompted by what they hear and like. Music has become to commercial like everything else in this country.
Popular music is selected by record exec's.
MTV exec's, etc. My parents got to live through the Beatles, the Who, Led Zepplin, Jimmy Hendrix, and countless other groundbreaking rock bands. Mainly because there isn't all that much ground left to break after the pioneers you cite and others got through innovating. As Edna Gundersen said in last week's chat, rock is half a century old and showing signs of age. And I should observe that the Who, Zep, Hendrix, Beatles, etc., also had to pass through a series of cultural gatekeepers like record execs, TV execs, radio programmers, etc., in their day.