>He's not making a point of "television makes you dumb" (or "dumb people watches television"), but rather he makes the distinction between an "oral"-, "press"- and "television"-based culture. He claims that it's bad when television becomes the main platform that a society centers its communication around.

Or as Postman himself put it, "the medium is the metaphor". And he strongly disliked the metaphor TV was bringing to bear on the Western World.

And everyone should note this is the television of the 1980s. You still don't really have home recording, there are a limited number of channels, and the monoculture truly exists.