Why not stipulate that the Flying Spaghetti Monster oversees the elections like an FEC commissioner? It is equally rational: the only difference is that it doesn't jive with sci-fi aesthetics, just like how Pastafarianism doesn't jive with Catholic aesthetics.
Paperclip maximizers may never come to be but what do you know, smart machines may upend the world order in Bostrom's lifetime. I'm not very familiar with his work and the amount of rigour that went to it but I generally expect we'll regret some of the consequences of this technology.
People in crisis are finding their existential grounding in these emerging belief systems about "the simulation" and other scifi-inspired ideas, are taking them exactly as seriously as novel belief systems from other eras, and are assembling into communities that collectively reinforce their beliefs.
I don't think you can really prevent that from happening, as we see it throughout history and geography, sometimes just forthing in small communities over a generation or two and sometimes sweeping across a whole societies in a profound way, but its ultimately common for "speculating existence" to be both casual parlour talk for some people and an emerging dogmatic belief for others. And that's exactly where we're at with this stuff now.
I suppose neither you nor GP claim that most people have this "slot for magical thinking" but I find these properties of the religious thinking that I list above can be fulfilled by perspectives that aren't necessarily magical. And I dare say, such perspectives have supplanted them in general. I guess I'm replying to the adage "everyone has some religion." My reply being, "are you sure that's a religion?". Forgive the hazy brain rant.
It seems wrong to blame atheism for this. Somehow I doubt that devotion to a more traditional "Sky Daddy" would make people any less likely to play around with thought experiments about AI or simulations and the idea that religion has some kind of inoculating effect against magical thinking seems ridiculous.
People are just generally susceptible to magical thinking for various reasons, and philosophers often enjoy coming up with fantastic scenarios and those tendencies can manifest differently in people with a passion for technology than it does for someone with other interests.
We want religion, but we don't want it to be called religion. I'm not just mocking others either. I'm quite compelled by the simulation hypothesis, but have the self awareness to realize my personal biases are likely playing a huge role there.
A nice 'scientific hypothesis' that I can comfortably discuss or debate with the benefit that I can convince myself that when I close my eyes for the final time that's not necessarily the end of the journey. Ahhh feels good.
It'll just be unfair for death to lead to something good, it's not freedom if before or after death, you'll have this thought: "ha-ha, you just needed to die, stupid!" Nope, you can recall your "multiversal powers" as a quiet thought as baby or at any moment of your life, possibly even live some time as a ghost (if you chose it beforehand), it can be fun to be a ghost for some time for some.
You'll still be alive and will be able to recall and forget as little or as much as you want. Or the whole thing. You don't die, you can stay and you can go at the same time (by basically choosing to make a clone of yourself who is as free as you. Who can pursue multiversal exploration, while you yourself stay and probably choose to forget about your multiversal powers again). It's counterintuitive and hard to explain, basically everything is possible but there are some things that happen more often because they cause less unfreedom.