Sure, you got me: "materialism" to me means "doesn't contain random bullshit that by its very definition can't even be investigated."

The moment someone offers a theory that says something concrete about any effect, it becomes "materialism." Most people pushing non-materialistic "techniques" really mean that we should throw our hands in the air and claim that we can never know how a thing works. And this is justified by claiming that modern science fails to explain mystical "effects" that nobody can even measure in a concrete way.

Put another way, suppose you're wrong, and there's no such thing as experience, and it's just an illusion of the brain that makes you believe there is - is this consistent with all of modern science? AFAIK, it is, in which case I see no justification to claim that modern science has failed.

Myself, all the evidence I've seen says that the functioning of the human brain (which is physically undistinguished, containing nothing that pushes the limits of the physics that we understand very well today) is governed by laws that we actually have a shot at understanding. I'd place good money on the fact that nothing about the brain's inner workings is influenced to any meaningful degree by any physical effect that we don't already have equations for. The only trick is understanding the large scale behavior, due to the incredible complexity.

The simulation shows nothing if you do this

Such a simulation would prove plenty - it would prove that we can approximate human behavior as accurately as we want to without including magic in the equation. You may still claim that we haven't accurately modeled the magic parts of the brain, but if they're unobservable from the outside, nobody doing anything useful really cares about the difference, and the onus is on you to prove that there is one at all, not on me to prove that there isn't.

Realize that you're claiming something extraordinary, that there is a fundamentally non-physical effect at work in the brain. This type of claim requires a lot more than a person's assertion that they experience it themselves to be credible, because people's claims about their inner states are notoriously misguided even about far less philosophical things.

If you irrationally deny that we can "measure" (i.e. establish) the existence of our own conscious experiences, and then refuse to incorporate any notion of experience into your simulation, you are clearly rigging the game in favor of materialism at the outset, not providing any argument for it.

Irrational? I disagree.

How might I "measure" the existence of subjective experience? Introspection absolutely does not measure it; rather, introspection measures my belief that I have experience, and the human brain believes a lot of things that are not true, so I can't put too much weight in that.

There's a crucial difference between the existence of a state of experience and the belief in the existence of a state of experience. I have yet to hear any coherent argument that provides evidence of the former, and the latter would be trivial for a good brain simulation to achieve.

It has to be said, though, that the idea that any straightforward notion of "observability" plays a role in science has been known to be highly problematic since the 20s, for basically the reasons that Quine and Duhem identified.

Without going too far into the details of Duhem-Quine, I'll just mention that this may bother philosophers of science, but physicists have elucidated many more useful, exploitable truths in the past four centuries by observing the world than the philosophers have over several millenia by thinking about it.

I am observing my own conscious experience right now.

Not really. What you are doing is believing that you are observing your own experience right now. That's it. Since there's no definition of "your own experience" on the table, I can't really comment on whether or not your belief that you are observing it has any correlation to the existence or non-existence of the state. But the burden of proof has to be placed on the person arguing for the introduction of a new effect, not on the person arguing against it, and I would claim that current (materialistic) theory has already adequately accounted for your belief in subjective experience.

In other words, introspection doesn't prove anything other than that you hold a particular belief. The messed up thing is, this doesn't only apply to my thoughts about your inner state, it has to apply to my thoughts about my own inner state as well; I can be no more sure that I have any extra-material subjective experience than I am that you do based on your assertion that it is so.

We have as yet no hint of a physical explanation for why I should be having such an experience.

True enough. But we have plenty of perfectly good physical explanations for why you might believe you're having such an experience, and without some other evidence that you're actually having that experience, we have to assume that the simplest and most likely explanation is that your belief is just wrong.

Just to be clear: I'm not altogether opposed to the idea that we can accept "subjective experience" as "real", for a certain definition of each term. But I do have a problem assuming that there's something that's even worth modeling or theorizing about; as best as I can figure, the most sense I can give to its reality is that it is as real as we believe it, and that the "experience" is really just the self-aware organization of information inside our brains, not some mystical interaction with an external entity or anything like that. Behaviorally speaking, both result in the same observable effects, and one requires fewer assumptions to explain the same observations, so...

Then again, Occam's Razor is another point where philosophers and scientists clash - philosophers want proof that every ludicrous possibility could not possibly be true, whereas scientists are just looking for evidence of what is actually the case, within a certain approximation. IMO the scientific POV has led to far greater successes, but YMMV.