Thanks to the wonder of the interwebs (just ask the pope) people are being exposed to all kinds of music and are discovering and enjoying many different forms of musical expression. That doesn't mean we should be forgetting about Rock & Roll. Rock & Roll never forgets.
The fact that Timberlake, Swift and others enjoy increased sales can be attributed to the dominance of corporate radio. Now that a handful of corporate players control music stations, you can expect the same, second rate, celebrity driven, tabloid style crap we've all come to expect from corporate news.