Irony Proof

Reading Matt Ridley's book The Rational Optimist: How Prosperity Evolves, he has this to say with reference to Plato:

The endless modern laments about how texting and emails are shortening attention span go back to Plato, who deplored writing as a destroyer of memorizing.

And Plato did it in writing. I wonder what that means?

Kierkegaard didn't think there was any point in trying to directly argue people out of the modern philosophical point of view.  Modern philosophy is irony-free because it is not subjective; to become subjective means to understand the meaning of irony. But whatever is said ironically can also be taken in its direct sense; we can, if we choose, interpret Plato as simply meaning directly what he wrote, as Ridley does. There is no way to prove, in any way acceptable to modern philosophical demands, that there is any more to Plato than this.

But, thank God, there is...