Eh, it's fair. I'd never want to lose Aliens because it's by far my favorite film (just, ever) but there's really no denying that the move to being more of an action film resulted in the franchises eventual downfall. We probably wouldn't have gotten Alien Resurrection, which would have been lovely. But then, honestly, it's not like the horror genre is really better at all for keeping sequels at the same quality. I'd rather have Aliens, Alien3 (which was okay. I guess) and Resurrection as a package than several more Alien sequels that start reaching Friday The 13th/Nightmare on Elm Street levels of shitty. (as in the sequels, not the first films)
Basically, what I'm saying is, we should probably just nuke the site from orbit. It's the only way to be sure.
James Cameron's Aliens was a sci-fi action movie abandoning the sci-fi horror genre that Ridley Scott established in the first film. The first film is no doubt a classic but I also love the second film. The Space Marines really are the selling point of that film. Alien 3 tried to bring the series back to it's roots. The less said about Alien Resurrection the better. I don't know how I feel about Prometheus. I don't know if I really want to know the origins of the Space Jockey. I kind of like the mystery surrounding them in the first film and would like to leave it at that.