In the specific case of leakage, even if it is a problem that persists far into the future, it just slightly lowers the growth exponent as we just somewhat lower the clock speeds.
I disagree; I think that problems like this, unresolved, may or may not decrease the base of our exponent, but will cap its growth earlier.
I don't think that any single such current technical issue is nearly sufficient to change the general analysis. There have always been major issues on the horizon, the question is more of the increase in engineering difficulty as we progress vs the increase in our effective intelligence and simulation capacity.
On this point, we disagree, and I may be on the unpopular side of this agreement. I don't see how past increases that have required technological revolutions can be considered more than weak evidence for future technological revolutions. I actually think it quite likely that increase in computational power per Joule will bottom out in ten to twenty years. I wouldn't be too surprised if exponential increase lasts thirty years, but forty seems unlikely, and fifty even less likely.
Imagine if we could go back in time and alter our primate ancestors to reduce their suffering. The vast majority of such naive interventions would cripple their fitness and wipe out the lineage. There is probably a tiny set of sophisticated interventions that could simultaneously eliminate suffering and improve fitness, but these altered creatures would not develop into humans.
I don't care. We aren't talking about destroying the future of intelligence by going back in time. We're talking about repeating history umpteen many times, creating suffering anew each time. It sounds to me like you are insisting that this suffering is worthwhile, even if the result of all of it will never be more than a data point in a historian's database.
We live in a heartbreaking world. Under the assumption that we are not in a simulation, we can recognize facts like 'suffering is decreasing over time' and realize that it is our job to work to aid this progress. Under the assumption that we are in a simulation, we know that the capacity for this progress is already fully complete, and the agents who control it simply don't care. If we are being simulated, it means that one or more entities have chosen to create unimaginable quantities of suffering for their own purposes---to your stated belief, for historical knowledge.
Your McDonald's example doesn't address this in the slightest. You were already a living, thinking being, and your parents took care of you in the right way in an attempt to make your future life better. They couldn't have chosen before you were born to instead create someone who would be happier, smarter, wiser, and better in every way. If they could have, wouldn't it be upsetting that they chose not to?
Given the choice between creating agents that have to endure suffering for generations upon generations, and creating agents that will have much more positive, productive lives, why are you arguing for the side that chooses the former? Of course the former and latter are entirely different entities, but that serves as no argument whatsoever for choosing the former!
A person running such a simulation could create a simulated afterlife, without suffering, where each simulated intelligence would go after dying in the simulated universe. It's like a nice version of Pascal's Wager, since there's no wagering involved. Such an afterlife wouldn't last infinitely long, but it could easily be made long enough to outweigh any suffering in the simulated universe.
Many folk here on LW take the simulation argument (in its more general forms) seriously. Many others take Singularitarianism1 seriously. Still others take Tegmark cosmology (and related big universe hypotheses) seriously. But then I see them proceed to self-describe as atheist (instead of omnitheist, theist, deist, having a predictive distribution over states of religious belief, et cetera), and many tend to be overtly dismissive of theism. Is this signalling cultural affiliation, an attempt to communicate a point estimate, or what?
I am especially confused that the theism/atheism debate is considered a closed question on Less Wrong. Eliezer's reformulations of the Problem of Evil in terms of Fun Theory provided a fresh look at theodicy, but I do not find those arguments conclusive. A look at Luke Muehlhauser's blog surprised me; the arguments against theism are just not nearly as convincing as I'd been brought up to believe2, nor nearly convincing enough to cause what I saw as massive overconfidence on the part of most atheists, aspiring rationalists or no.
It may be that theism is in the class of hypotheses that we have yet to develop a strong enough practice of rationality to handle, even if the hypothesis has non-negligible probability given our best understanding of the evidence. We are becoming adept at wielding Occam's razor, but it may be that we are still too foolhardy to wield Solomonoff's lightsaber Tegmark's Black Blade of Disaster without chopping off our own arm. The literature on cognitive biases gives us every reason to believe we are poorly equipped to reason about infinite cosmology, decision theory, the motives of superintelligences, or our place in the universe.
Due to these considerations, it is unclear if we should go ahead doing the equivalent of philosoraptorizing amidst these poorly asked questions so far outside the realm of science. This is not the sort of domain where one should tread if one is feeling insecure in one's sanity, and it is possible that no one should tread here. Human philosophers are probably not as good at philosophy as hypothetical Friendly AI philosophers (though we've seen in the cases of decision theory and utility functions that not everything can be left for the AI to solve). I don't want to stress your epistemology too much, since it's not like your immortal soul3 matters very much. Does it?
Added: By theism I do not mean the hypothesis that Jehovah created the universe. (Well, mostly.) I am talking about the possibility of agenty processes in general creating this universe, as opposed to impersonal math-like processes like cosmological natural selection.
Added: The answer to the question raised by the post is "Yes, theism is wrong, and we don't have good words for the thing that looks a lot like theism but has less unfortunate connotations, but we do know that calling it theism would be stupid." As to whether this universe gets most of its reality fluid from agenty creators... perhaps we will come back to that argument on a day with less distracting terminology on the table.
1 Of either the 'AI-go-FOOM' or 'someday we'll be able to do lots of brain emulations' variety.
2 I was never a theist, and only recently began to question some old assumptions about the likelihood of various Creators. This perhaps either lends credibility to my interest, or lends credibility to the idea that I'm insane.
3 Or the set of things that would have been translated to Archimedes by the Chronophone as the equivalent of an immortal soul (id est, whatever concept ends up being actually significant).