Why consider BM at all? Well, I’d argue that it gives us insight into what a hidden variable theory has to look like to reporduce QM and it is a good source of counter-examples for a lot of gumph that people claim about quantum theory. Advocates would argue that it gives one a clear picture of what is going on in the world, and avoids the ubiquitous measurement-talk of standard interpretations. On the other hand, the postulation of degrees of freedom that can’t necessarily be directly observed is a good reason for being skeptical in my opinion, although that’s only a cartoon sketch of my reasoning.

For BM to agree with QM something called the “equilibrium hypothesis” has to be true. If we drop this hypothesis then BM is more general than QM, and makes different predictions. This is very much like the difference between equilibrium and non-equilibrium statistical mechanics. However, not observing these discrepancies is no reason for rejecting BM, since we may be in an analog of the “heat death” in which only equilibrium states exist. I don’t have time to go into this now – maybe in another post.

In fact, there have been a number of attempts to find a testable contradiction with QM. These mostly concern “empty waves” and usually rely on unfounded assuptions about Bohmian mechanics.

To be fair, I do think it is one of the more sane interpretations on the table. It also now has a couple of different reasonable extensions to QFT, which have been developed in the last few years. This was one of the biggest outstanding problems for the theory.

I am very much interested in the foundations of QM. Could you point me to some relevant books/papers regarding the thing you quoted? For I thought that Bohmian mechanics was consistent with (most) experimental observations?