Not even a huge fan of the Alien franchise, but the idea that David created THE Xenomorphs is the lamest, most nonsensical retcon to happen to any series ever. It's a thousand times worse than anything George Lucas ever did at least with regards to the overall plot implications. So not only does that make the LV-426 derelict no more than <28 years old (retarded—it's ancient), but we're forced to assume an Engineer (whose civilization was implied to have gone extinct ~2000 years ago in Prometheus) decided to load David's creations into a Juggernaut ship➙