He didn't grasp that speech and text were the same in terms of arbitrariness, and he couldn't see that narratives are basically illusions in terms of their meaning-load. We know from neurosci any event has two dimensions of meaning, where it carries in past memories already formed, and how it creates local memory in formation. Both are probably limitless, yet narratives ascribe intent and cause and effect to essentially turn us into meaning zombies, forever revisiting the same unidimensional intents and meanings as if they are applicable to real events. They simply aren't. Literacy is dead for reasons McLuhan could not have imagined. He never reached the leading edge of demythologization, which is where we are, and how literacy dies.