Appeal to authority is a logical fallacy. People often fall into the trap of thinking that because they are highly intelligent and an expert in one domain that this makes them an expert in one or more other domains. You see this all the time.

> People often fall into the trap of thinking that because they are highly intelligent and an expert in one domain that this makes them an expert in one or more other domains.

While this is certainly true, I'm not aware of any evidence that Carmack thinks this way about himself. I think he's been successful enough that's he's personally 'post-economic' and is choosing to spend his time working on unsolved hard problems he thinks are extremely interesting and potentially tractable. In fact, he's actively sought out domain experts to work with him and accelerate his learning.

Bayesian reasoning isn't a fallacy. A known expert in one domain is often correct about things in a related one. The post didn't claim that Carmack is right, just that that he's who they would bet on to be right, which seems perfectly reasonable to me.

Expecting an expert in one thing to also be pretty good at other domains, especially when they're relatively related, isn't a fallacy.