I dunno. Are we talking about true "hard AI"? Because really, how much can Sussman or anyone introspect their own thought processes? We can tell ourselves stories about motivation and symbol manipulation, but those stories themselves are just more symbol manipulation. I'm not sure a sentient symbol-manipulator ever really "gets to the bottom" of true introspection of their own thought processes, including counterfactual thoughts they might have had.
This seems like an overly mechanistic approach, although perhaps workable in "soft AI"