Without humans there would be no hunt, The yautja have been to most of the planets in the galaxy most likely and they find humans are close to what they are, and they see them as a worthy challenge. The yautja are like the Samurai with their code of honor, and like the Spartans because they can withstand most attacks. and as for AVP:Requiem, Wolf was in it long enough, he died honorably, unlike in the first AVP you could tell what his story was just by how he looked, also what do you expect when an xenomorph infestation is in a city in the U.S.? They would show alot of humans. mostly getting head bit or having chestbursters come out of them, or being shot by a plasma caster. The only problem I have with it is that it was mainly at night, unlike in AVP where there was a sufficient lighting.
Hey leave Starscream alone! He's been through enough, and you can't judge a book by it's cover. Sure it's another movie with the yautja but that doesn't mean it's gonna be dumb. Granted Predator2 wasn't as good as the first but it was still good, and both AVP and AVP:Requiem were really good. They make sense in a way, especially if you know the whole history of the yautja. The new Predators movie will be good. They're a new generation of hunters that will(if any survive) continue hunting after they're trail hunts. They would still have to go through the Kainde Amedha Chiva to become a full blooded warrior though.