Predators shouldn't be anthropomorphisised. Sil's right, in my view; you can't apply our moral standards to them, because those are patently not the standards they operate by. We don't even have any indication that they would so much as comprehend them, let alone agree with them.
Their trophy cabinets are stuffed full of what they regard to be 'worthy' challenges. They're testaments to the heat of the moment. If anything, that, combined with the reverential appearance of how they stroke the brow of cleaned skulls and wear them, could be said to infer that they regard such things as honouring those they've faced, not disrespecting them.
Predator psychology is, no matter how many ways you bend it, a very alien psychology, in every sense of the phrase. You can't analyse it like you would with a human, because they aren't human.
We're in the same trophy cabinet as they put Alien heads and just about anything else they find: Predators do not care how intelligent your culture considers itself. To them, it does not, must not and has no reason being, factored into the hunt. You're either a target or you're not. The only rule seems to be whether you'd fetch zero or bonus points.
They're no more psychopathic, than ants are for taking slaves or dolphins for casually indulging in gang-rape and infanticide. If humans operated like that? Sure, we could level that accusation at them, but they're not human and never will be.