I've seen some of his stuff. I am reacting to a talk where all he says is "this is wrong". I've written about some of that stuff in other posts here, so I won't duplicate it. He by and large argues to throw math away, and shows toy examples where he scrubs a hard coded constant to change program behavior. Almost nothing I do depends on something so tiny that I could scrub to alter my algorithms.
Alan Kay is awesome. He did change things for the better, I'm sorry if you thought I meant otherwise . His iPad sketch was of something that had immediately obvious value. A scrubbing calculator? Not so much.
Next, read the following essays of his: Explorable Explanations, Learnable Programming, and Up and Down The Ladder of Abstractions
Do you still think he's all talk?
Also, I can't tell if you were implying otherwise, butAlan Kay did a few other notable things like Smalltalk and OOP.