[tmvphil]

I can't speak for other quantum theorists, but pilot wave theory does nothing to make multi-particle entanglement less mysterious. It provides a nice story for wave-particle duality, but for a long time it has been apparent that this is not the central mystery of quantum mechanics.

[jostylr]

It does focus the discussion clearly on the wave function as defined on configuration space, bringing to the front the importance of position.

But mostly the reason is that if you are going to develop a better theory (namely how relativity and qm work together), then it may be helpful to start on a clear foundation where irrelevant confusions have been eliminated.

For example, the role of operators is derived in pilot wave theory, not assumed. This greatly simplifies the issues of putting quantum mechanics on curved space where the Fourier transform may not be so easily defined, if at all. You do have to worry about the Hamiltonian and its boundary conditions, which is part of the physics of the space, but the relevant measurement operators are derivable from the ported theory.