Problem is, there's no such thing as a "non-human person"...
...in real life, so there shouldn't be in law either.
Or, if you want to see it from another angle: OK, "non-human persons" exist in law, which means they exist for real. But who says morality should be an attribute of biological humanity?!? I say, it's an attribute -- a requirement -- of personhood.
So, sure, those who advocate corporate personhood (and yes, Jack, I'm fairly sure you didn't mean to imply you're one of them) may actually have a point and might after all have it their way -- as long as they concede that this means these figments of the judicial imagination are at least as required to behave like upstanding citizens as are the rest of us, and ought to be at least as punishable-by-death as any physical person.