It's probably just a natural consequence of modern distribution and reproduction. It's far, far easier to follow individual artists and genres now than it was in the past. For centuries, if you wanted to hear a particular song, you got your talented buddies to pull out their instruments. Performing other people's music was par for the course since it was pretty much the only way to keep a song alive and the songs naturally changed with the playing in due time anyway. These days, if I want to a hear Beatles song I just throw on the Beatles, which rather renders the efforts of others to recreate their work somewhat redundant. It's sort of like the way painting and drawing shifted somewhat after the development of photography. Traditional artists couldn't compete with the way photographs could represent the world around us, so instead many turned their attention to surrealism, abstract art and other more stylistic works. Novelty is basically the only value people can agree on as being worth something these days.
