As per a recent comment this thread is meant to voice contrarian opinions, that is anything this community tends not to agree with. Thus I ask you to post your contrarian views and upvote anything you do not agree with based on personal beliefs. Spam and trolling still needs to be downvoted.
Suppose we have two jars of qubits:
Half the qubits in jar (1) are in state |0> and the other half are in state |1>.
Half the qubits in jar (2) are in state |+> and the other half are in state |->.
Notice that although from a classical Bayesian MWI perspective the two jars are in very different states, there is no way to tell them apart even in principal.
BTW, that's the only reason why I'm not fully convinced by realist interpretations of QM.