Why? Taktile made a great comment (quoted below) over at Eschaton, where Atrios is pointing out the fallacies at the heart of media deregulation arguments.
The whole libertarian philosophy exists on the basis of pretending there's no such thing as market power (monopoly), negative externality (ie pollution), public goods (ie crime, safety) or asymmetric information (ie used car salesmen).
It's like how Marx responded to his critics, who told him that communism didn't account for human greed, by deciding that greed must have been created by capitalism and would vanish along with it.
It's the general human tendency that when your theory doesn't fit reality, you should change your perception of reality.
This general human tendency we call cognitive dissonance.