because he said so.

"when an artistic tradition reaches the point when literally "anything goes," those who want to be creative have a problem: there are no fixed rules to rebel against, no complacent expectations to shatter, nothing to subvert, no background against which to something that is both surprising and yet meaningful. it helps to *know* the tradition if you want to subvert it. that's why so few dabblers  or novices succeed in coming up with anything truly creative." (Daniel C. Dennett)