I always found the concept of an honor system interesting, but I don't want to see the predators humanized anymore or have another forced team up with us. The city hunter sparing Leona in the subway and not killing unarmed people is about the most we ever need to see of that kind of thing. As already said, mayne that was just their thing in that group. There's no saying that they would all necessarily act that way.
Predator 2 expanded the character without ruining or over explaining anything. All the weird details, even down to them occasionally talking (City Hunter when he notices something is off in the slaughterhouse, elder at the very end), just makes them more mysterious and interesting imo. Compare that to The Predator where we are shown and told how and why they do certain things, and we literally have subtitles for their speech, it just isn't the same. Not to mention abandoning the crazy unique ship design for the AVP style sleek generic stuff.
Predators was a middle ground for me. For what it's worth, I thought the hunting camp was a fantastic set.