Bostrom's accomplishment is to succeed at bamboozling many who felt they were beyond being bamboozled.
Bostrom is a charlatan playing rubes with an intellectual version of three-card monty:
//This paper argues that at least one of the following propositions is true: (1) the human species is very likely to go extinct before reaching a “posthuman” stage; (2) any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history (or variations thereof); (3) we are almost certainly living in a computer simulation. It follows that the belief that there is a significant chance that we will one day become posthumans who run ancestor‐simulations is false, unless we are currently living in a simulation. A number of other consequences of this result are also discussed.//
What is a post-human stage of development?
Is human extinction a post-human stage of development?
How did this argument get from post-human to ancestor simulation? It's stipulated in a lemma.
What is a simulation according to Bostrum? Undefined.
What then is an "ancestor" simulation?!
The weaseling on display adds gross insult to intellectual injury:
How unlikely is "extremely unlikely"? What is a "significant number" of ancestor" simulations? What is "evolutionary history"? How did he get from ancestor simulation to computer simulation?
Who else can stake an academic reputation on tenets delivered in the form of afterthoughts?
A theory must contain a promise of making matters simpler. If there's any kind of theory associated with Bostrom's argument, it's that many people can't distinguish a theory from an arbitrary collection of intriguing statements. Bostrom is functioning as an academic instance of Weisenbaum's Eliza: it just circularly echoes its own kooky conjectures in the form of lemmas and an outwardly spiraling discussion of itself.
Bostrom is playing a silly joke on readers. He gives his game away with his ridiculous lemmmas, showing the ace during the shuffle:
"It follows that the belief that there is a significant chance that we will one day become posthumans who run ancestor‐simulations is false"—period.
So, what was the question which was to be begged? Read it and weep. You've been played.
You've got to hand it to a magician / mentalist who gets his audience to believe they are as "worms wiggling in the ground with no conception of god-like beings that inhabit the world".
The most pitiless aspect of this fantasy is that it includes a proposition for what man is unaware of in the form of the overt statement of that which he is unaware: "god-like beings" Could the question of faith be any further begged? It's deranged.
Here we encounter Zizek's fourth quadrant of Rumsfeld's knowns: the "unknown knowns." Ideology. That which you know but avoid or refuse to become aware that you know to keep your faith alive.
There's a rule about the actual unknown, which is that it must be literally about the which is not known!
More generally, as to what is not known, we can only poke at the edge of a lacunae, maybe inferring something about the contours or gradient to mystery, maybe following the edge to refining our adaptation to ourselves. But our work doesn't belong with the unknowable. It belongs with what we can know about ourselves. The unknown will take care of itself.