Which is an intriguing argument considering he .. wrote it down and not just once. He was a prolific author. He also speaks _through_ other people, mostly Socrates, which complicates matters quite a bit. You're getting a narrative as told by someone inside the narrative about the nature of narration itself.
I'd be hesitant to linearize Plato. There's quite a bit of subtlety to his arguments.
That said, I understand the sentiment. Just want to introduce some nuance into the statement. I'd hate it if people thought Plato could just be pinned down like that.