While I agree that they definitely don't belong in the human box, they don't belong in the monster box either. That sort of implies that they're just aimless, destructive beings with no real goal or reasoning behind their actions (like other "monster movies"). They are intelligent life forms (both Aliens and Predators), the Predators especially with a high form of self awareness and complex civilization. Yeah sure, if you see them as "monsters" that will limit their scope and arbitrarily self-confine them into a certain narrative. Properly, they're "aliens" - they're allowed to operate as individuals, with their own codes, regardless of how well or not they match up to humans. This opens them up to do more, rather than being confined to mindless hack and slash, which we've already been shown they are not through their hunting culture/independent decision-making/etc. The possibility is already there. If the franchise wants to go that direction, great! They have a basis for it. If they don't, that's cool too, cause they have a basis for it also.