Well he didn't say exactly that. I remember reading a quote from a long time ago, he said he didn't read sheet music and had no interest in it because you can't write emotion into sheet music.
ya alot of these contemporary musicians make claims like that, and its idiotic. I know what theyre getting at, its about emotion and not just "theory" or technicality, but notated music is a worldwide system for communicating music to other people. Its the easiest most efficient way to learn music, not mention the easiest way to study and understand it.