This argument would fall apart if we could simulate a human mind, and there are good reasons to think we could. Human brains and their biological neurons are part of the physical world, they obey the laws of physics and operate in a predictable manner. We can replicate them in computer simulations, and we already have although not on the scale of human minds (see [1]).
It's on Penrose and dualists to show why simulated neurons would act differently than their physical counterparts. Hand-waving about supposed quantum processes in the brain is not enough, as even quantum processes could be emulated. So far, all seems to indicate that accurate models of biological neurons behave like we expect them too.
It stands to reason then, that if a human mind can be simulated, computers are capable of thought too.
Hand-waving is not required as one is not going into microfoundations at all in the original argument. Someone making a thermodynamic argument for some conclusion, can later on try to speculate about how the conclusion is implemented with statistical mechanics. But the original argument is itself independent. Similarly, Penrose speculates about Orch-OR(which is not dualism btw, Penrose is a physicalist), but the truth of the argument isn't dependent on Orch-OR itself.
It's on Penrose and dualists to show why simulated neurons would act differently than their physical counterparts. Hand-waving about supposed quantum processes in the brain is not enough, as even quantum processes could be emulated. So far, all seems to indicate that accurate models of biological neurons behave like we expect them too.
It stands to reason then, that if a human mind can be simulated, computers are capable of thought too.
[1] https://openworm.org/