Point taken regarding ancestor simulations, but I don't think that resolves the question. What we choose to do is still evidence about what others will choose to do whether or not the choice is about simulating ancestors or just other possible worlds. [...] In Bostrom's formulation there is also the possibility that civilizations capable of ancestor simulations will overwhelmingly choose not to. It's not obvious to me that this is one of the horns of the trilemma to reject. I can think of at least two reasons why it might be a convergent behavior not to run ancestor simulations: 1) Civilizations capable of running ancestor simulations might overwhelmingly have morals that dissuade them from subjecting sentient beings to such low standards of living as their ancestors had. 2) Such civilizations may wish to exert acausal control over whether they are in a simulation. This is the motivation for my question.

I strongly recommend not using stupid. It's less distracting to just point out mistakes without using insults.