There's plenty of new music that doesn't "sound the same" - Clear Channel just won't play most of it, and therefore it's not considered "pop" (The Lumineers, for example, are currently #27 on ITunes, just off Alternative play)
Don't understand the loudness thing - if you turn Rihanna up to Volume 30 on your car stereo, it's just as loud as turning the Rolling Stones up to Volume 30 - is this article trying to prove that people LISTEN to modern pop music at louder volumes?

I don't think it's fair to count Clear Channel as the only one not playing certain genres/artists - I don't hear Cumulus, and certainly not CBS jumping on anything "different"...
In fact, I listen Channel 96.1 in Charlotte daily and they aren't afraid to step outside of the rhythmic pop genre that dominates the CHR charts. They added the latest from Fun., Matchbox 20, and Train quickly, just an example. Fortunate to get them well here as my hometown CHR (B-93.7) is a little more rhythmic and continues to be slow and dull (seriously, "Boyfriend" in power rotation while nearly ignoring Ellie Goulding?).