Right. I think he is mixing up a few different but related things. One is the ability for computers to do causal reasoning at all, such as an if-then statement

Right. I think he is mixing up a few different but related things. One is the ability for computers to do causal reasoning at all, such as an if-then statement or Prolog program. The other is the ability to do it in a general purpose way in open-ended domains and tasks. We have machine learning that can learn in a somewhat open-ended way given enough example inputs and output examples. But that type of system usually isn't good at causal reasoning, because the "understanding" it has of the world is shallow and inaccurate. There is no evidence that it's impossible for an AI to write a novel. It's just clear that existing systems are not currently close. But we can create toy domains with successes that make me optimistic. Anyway I think the author has misunderstood some fundamental things and embarrassed himself with this article.