And here's why:
Santiago now phrases this in her terms: "Art is a way of communicating ideas to an audience in a way that the audience finds engaging." Yet what ideas are contained in Stravinsky, Picasso, "Night of the Hunter," "Persona," "Waiting for Godot," "The Love Song of J. Alfred Prufrock?" Oh, you can perform an exegesis or a paraphrase, but then you are creating your own art object from the materials at hand.
Here he is essentially saying "I myself cannot understand what message might possibly be contained in the works of these great masters, or in these great poems, therefore there is none." Yet any of us who did ANYTHING in college other than watch movies understand that these pieces and artists are of profound artistic significance. By citing these great artists and works of art as idea-less (read: meaningless) he disqualifies himself from being allowed to make ANY future comments on what is or is not art, and thereby making his "Video games can never be art" statement invalid.
ergo: Ebert = Idiot.