I think the questions surrounding the 'birth' of the aliens are enough fodder to have this film be a bonafide and official prequel. This film takes place in the same universe, discovering the same space jockey and goes deeper to figure out who they are and what happened to them. To me, that is in essence, a prequel. Discussing the term Alien...that encompasses quite a bit, space jockeys and all. I feel like people want the word 'alien' in the title to convince them that this is an alien film.