quantum mechanics - Interpretations of Stern-Gerlach experiment

In many textbooks (J.J. Sakurai for instance) S-G experiment is explained through the idea of a collapse of a state of a system. So here, in this discrete case, we can see quantum behavior more clearly than with wave functions. We can interpret results of the experiment by saying that spin state of a particle is not defined, particle is in spin1 and spin2 state, in a superposition of two states, and its state collapses into one of these two when measured ( meaning when passing through magnetic field). My question is this: What other interpretations can anyone offer, and why would anyone invoke consciousness when it is clear that here magnetic field plays a role and not observer? How would other interpretations of QM interpret this? Bohms or any other?