In my opinion, rock has this melody to it in most songs (like the Pink Floyd I'm listening to now) while pop has the same, pretty much generic beat in all songs. It feels like you've heard the song before; nothing's new. I like maybe 4-5 pop songs, but that's all.

Plus, rock is wide-ranging, from emo to simple piano rock, hard rock to psychedelic. I'm 14 and quite frankly, while people think Lady GaGa and Bieber are all there is, there's still some rock out there. Just search and you'll find it! My musical tastes tend to fit neatly in 80s and 90s hard rock, despite my age :)