The real problem was not leaving Ripley alone after Alien 3. She had her arc and it was pretty much perfect. A:R took that away from her. As for the AvP films, I'm old school. They are spin-off's pure and simple. You don't create a multiverse into a series that has no grounds for it. My biggest hope for Alien 5 is that Blomkamp goes down the route of a new story in the universe, not create things that will overlap or breakdown the originals.