...it has AI-Einstein miraculously picking the correct needle out of an infinite haystack. But it's a fiction story, and so horrendously improbably things are allowed to happen.

I've been making similar complaints for years. And the replies I get are along the following lines:

Skeptic01: X is a highly conjunctive hypothesis. There's a lot of hand-waving, and arguments about things that seem true, but "seem true" is a pretty terrible argument.

LW-Member01: This is what we call the "unpacking fallacy" or "conjunction fallacy fallacy". It is very easy to take any event, including events which have already happened, and make it look very improbable by turning one pathway to it into a large series of conjunctions.

Skeptic01: But you are telling a detailed story about the future. You are predicting "the lottery will roll 12345134", while I merely point out that the negation is more likely.

LW-Member02: Not everyone here is some kind of brainwashed cultist. I am a trained computer scientist, and I held lots of skepticism about MIRI's claims, so I used my training and education to actually check them.

Skeptic01: Fine, could you share your research?

LW-Member02: No, that's not what I meant!

LW-Member03: Ignore him, Skeptic01 is a troll!!!

...much later...

Skeptic01: I still think this is all highly speculative...

LW-Member03: We've already explained to Skeptic01 why he is wrong. He's a troll!!!