If the thargoids arrived when CMDR's were there, and we could try and stave them off, that would be a lot better entertainment.... Hell leaving the players to be incharge of organising humanities defense would be really emergent gameplay.
Agree: you kinda expect that to be in a game, right? You know, make a game so that it is engaging for the players. This 2.4 release is pretty much all about NPCs battling each other - in battles that we never see... But hey, at least us human (players) are here to clean things up doing the dirty and dull stuff (hey, isn't this something for robots to do?).