I understand that's the interpretation, but I don't observe the dead cat, so I don't feel compelled to accept MWI. I'm not saying it's wrong (who knows), only that it's not scientific (lacking empirical evidence for the dead cat) and one of the other interpretations could be correct (again who knows if any of them are representative of the true state of affairs).
The two cats are what the Schroedinger equation implies. The fact that you don't observe the dead cat is perfectly consistent with the Schroedinger equation. To deny the dead cat means that the Schroedinger equation doesn't describe physical reality, and that it has to be modified or added to in some way. There are ways to do so, but it makes the underlying model more complicated and more awkward. Occam's razor would suggest that the Schroedinger equation is the simplest and most parsimonious explanation for what we observe, despite it also predicting the unobservable (for us) other branches of the wave function.
I understand, but Schrodinger himself came up with the cat thought experiment to demonstrate that he felt something was obviously wrong. A version of the Copenhagen interpretation would just say the wave equation is a useful tool for predicting experimental outcomes. We can't say what's really happening when we're not observing. So you don't need to add anything, you just give up on saying what's real. Which seems defeatist or anti-realist, but then one can always hold out hope for better experiments to one day show us what is really going on.
As for parsimonious interpretations, what does superdeterminism add?
