The issue is that basically claims non-locality. If our problem is an inability to locate particles, then our local space is defined by something else, by things which cannot be pinpointed in our immediate vicinity.

It also effectively claims a hidden variable: if only we knew this hidden state we can never know about, then we could recognise how an electron was pre-determined to hit the screen. — TheWillowOfDarkness

What's the QM problem? Why is it a problem that the result is indeterministic (better said probabilistic)? — Agustino

The problem with indeterminism as currently defined (exact sets of causes can have variable effects) is incoherent to me. It seems to violate basic causation, a fundamental concept for our comprehension of the world (ala Kant). So, my inclination is to accept any expert's rejection of QM indeterminism just because all else is incomprehensible. — Hanover

That's the motivation for Many Worlds — Marchesk

"This shows the interpretation, while being causal is not strictly deterministic. [Bohm's italics]. Indeed in the next chapter it will be shown that the possibility is opened for creativity to operate within a causal framework." — Rich

De Broglie's views — Rich

There's also Pilot Wave theory which removes the non-determinism and collapse issue, but at the cost of non-locality. The theory is quite simple in that it supposes that each particle interacts with a guiding field. So, say, the particle always passes through one of the slits in the double slit experiment, but the wave passes through both and hence interferes with the particle's motion. — Agustino

That's the motivation for Many Worlds, btw. It removes the collapse issue, but at a cost of postulating a vast number of branching worlds that we can't interact with. But if you're willing to roll with that, it works. — Marchesk

There is also a slew of results that refute hidden-variable theories of any kind, not least the Free Will Theorem. — tom

Sure, what I mean is that it's a pretty big metaphysical bullet to bite. — Marchesk

It's not metaphysical in the slightest, it's the real physical situation. — tom

And, the other worlds are required to explain what we see in this world in terms of interactions with them - i.e. it is a testable prediction. — tom

It's not metaphysical in the slightest, it's the real physical situation. And, the other worlds are required to explain what we see in this world in terms of interactions with them - i.e. it is a testable prediction. — tom

It sounds a bit like the hidden measurement interpretation (https://en.wikipedia.org/wiki/Hidden-measurements_interpretation) — Gooseone

There wavefunction is not real. Rather, our uncertainty about the exact quantum state (which is classical in Binney's interpretation) is translated to the particle or particles in these experiments. — Marchesk

From my reading, Bohr met every one of Einstein's challenges along these lines (as detailed in Manjit Kumar's book Quantum).The final nail in the coffin was Aspect experiments which falsified the EPR conjecture. — Wayfarer

So no fundamental indeterminism, no pilot waves, no non-locality, no other worlds, and no weird collapse.
...
We just can't precisely measure the molecular arrangement of the screen. — Marchesk

It is a hidden variables approach, just not of the particle, and its non-classical. — Marchesk

I'll restate it briefly. There wavefunction is not real. Rather, our uncertainty about the exact quantum state (which is classical in Binney's interpretation) is translated to the particle or particles in these experiments. If we could take into account the exact state of the measuring device, then the uncertainty of the particle's property in question would dissipate, and thus there would be no need for the wavefunction. — Marchesk