I think there's two slightly different angles to this question:
- is Orch-OR a good hypothesis that can and/or still needs to be tested scientifically?
- are the supporters displaying rationality and scientifically sound thinking in their arguments as opposed to crank/conspirational thinking plagued with selection bias and the like?
Starting with the first, an important aspect to grasp is that inapplicable experiments don't tell us anything - including that the original hypothesis was necessarily incorrect. I haven't read the linked papers, but your description seems to point in this direction: we tried to test Orch-OR, and the tests didn't actually work in a way that tells us anything about how neurons within a brain behave. So, as a theory, it's standing is unchanged either way - and of course, if you don't buy the counter-arguments, then the experiments do boost its credibility.
Similarly, a theory being around for a long time without evidence either way does not necessarily have weight either way, especially if gathering evidence for it is very involved or difficult to do in a robust way. It took decades for Peter Higgs to get his Nobel even though he was completely correct.
It seems like the only way to falsify Orch-OR would be to identify all
of the entangled particles that are associated with a conscious
experience, to show that the wave functions of those particles
"collapse" at the same moment that a person has a conscious report,
and to repeat that experiment and to get the same result every time.
As an aside, you're basically correct that it's extremely hard to positively prove its negation, but that's a much higher bar than we normally use to reject theories. I have asked a question previously about what exactly motivates Orch-OR because I was (and still am) under the impression that effectively all motivation for it hinges on the Penrose-Lucas argument, which I believe is unsound.
IMO, this means that Orch-OR is not a particularly good hypothesis scientifically because - Penrose-Lucas being unsound - we have no good reason to think it is any more likely to be true than say, Russel's teapot. However, this is very crucially different than refuting it - we can dismiss it as unlikely to be true without counter-evidence because we have no evidence indicating it is true to begin with, but we cannot assume it is definitely false. That would be the best-named fallacy, the fallacy fallacy.
Additionally, the amount of evidence proverbially needed to "take Orch-OR seriously" is also higher than most hypothesis because it involves several implicit but wild corollaries:
- it commits you to a particular interpration of quantum theory, that wavefunction collapse is not only a real event that can be tested, but can be influenced by the state of matter beyond the Born rule - this alone should show up somehow in experiments if it were true, which means that adherence to standard quantum theory in other areas of science becomes counter-evidence by modus tollens.
- more importantly, it is, unavoidably and by design, uncomputable - it has to be to be compatible with Penrose-Lucas. This means it is by definition impossible to use the theory to make predictions about future results, which is arguably unscientific on its face because no amount of empirical evidence could justify such a thing. It certainly blows the process of science itself wide open - if you allow an "uncomputable" thing in the universe, its inherent unpredictability spreads, since if it is unpredictable, any effect it has on its surroundings is inherently unpredictable, which then leaves them in an unpredictable state to interact with other things, and so on. If Orch-OR is true, it follows inexorably that a physical theory of everything does not exist.
Despite this evidence, which is from numerous peer-reviewed
publications, articles in peer-reviewed journals continue to be
published that rely on those UV-vis tests as a basis for asserting
that Orch-OR has been "proven."
As for the supporters: I think unless you yourself are a reviewer for the journal, it is just difficult to confront researchers with any particular evidence and so, ironically, hard to test their opinion of it. You can't easily determine if they have simply not seen the counter-evidence, have seen it but don't buy the counter-arguments for whatever reason, or are cynically holding onto their belief and/or promotion of Orch-OR in the face of counter-arguments they can't refute.
That said, while I am not a scientist myself, from what science papers I've read, their authors are extremely averse to making claims like a theory being "proven" if it's anything less than a mathematically precise statement they have the data for. People using language more loosely than that might be similarly leaning towards less rigorous thinking, and with Orch-OR in particular there is a lot of ulterior reasons that people might want to believe it, cynically or not, rather than out of dispassionate weighing of scientific arguments.
Similarly, specious arguments about experiments that are consistent with Orch-OR being evidence of Orch-OR are a bad sign in terms of healthy scientific process and really come back to the seeming lack of motivation behind the theory - it only really makes sense to evaluate evidence "for a theory" in contrast to competing theory, where evidence for a theory A are events that theory A suggests should happen where theory B does not. Sure, mucking around with microtubles changing consciousness is consistent with Orch-OR... but normal materialist functionalism doesn't (currently) specify how the brain works in fine enough detail that it rules out exactly the same thing happening, and with no particular reason to think OOR is true, we also have no reason to think that that functionalism is false.
