I really hope Scott doesn't explain the alien ship or the Space Jockey.
He actually saion the Alien commentary track way back when that if they did another Alien movie it should be about that race, which was a trifle tongue-in-cheek (which in itself may cast doubts on the validity of this I dunno).
And my two cents... honestly, why not?
Is there some kind of rule that the Alien movies should only feature this one speicifc alien species? The only issue to me is whether or not they're able to execute it in an effective manner - in the original film (which I watched again last night as I am wont to do on Halloween) there's little surprise at coming into contact with aliens, but there's also a chasm of incomprehension.
If the Star Trek
franchise is about going out into space, confronting the unknown and discovering it can be not too dissimilar to ourselves, then Alien
is about discovering the horrible and inexplicable and incomprehensible in the skies beyond (that is, "The Corbomite Manuver" would end wth Balok eating the Enterprise crew, to use an awkward analogy). The Growers don't have to be malicious or cruel, but they do have to be strange and difficult to understand and communicate with.
I don't even necessarily object to 'men have sex but can't reproduce', since of course, a man is impregnated via fellatio and then gives birth via a rather messy Caesarean... not to mention the attempted rape-by-magazine by Ash on Ripley and the generally sexual undertones of Giger's designs. Body horror and uncomfortable and bizarre sexual practices are kind of iconically relevant to this franchise. Just got to be handled as pretty screwed up, really.
I love the Ripley character, of course, but why not have a different, even male protagonist, next time?
Because if there's one thing sci-fi films really lack, it's male protagonists.