Rock has become irrelevant, any popular "rock" music is basically pop these days. Most would be rock fans have realized that the real talent base in musicians is in metal. Most rock is just catchy pop riffs/chords played on actual instruments. It is watered down for the masses and so people can hum and sing along.
Is there anything inherently wrong with this? No, but most music fans realize what the industry is doing and it is not palatable to them. So they are forced to live in the past or accept the new wave of music.
While I am no where near a fan of the music there are no more Zepplins, AC/DC's, or Beattles left in the world. There are only Beiber's, Kanye's, and Lil Waynes along with some actually talented musicians who will never be heard by the masses because they are too stupid to listen.