I'm thinking more of the 'inner mythos' of the thing which is largely to do with the impact of certain key images on a more folkloric zeitgeist. I doubt any director or screenwriter could capture that on their own - anymore than one guy could write The Bible. The stark simplicity of Alien allowed it to come through as pure illumination, whereas Prometheus was over-written to the point that the only 'hope' in that sense was the prospect of a spacejockey homeworld. I appreciate these 'meaningful questions' have an appeal, but ultimately the most meaningful things are unsayable and the most meaningful films are the most meaningless. Alien is one such film.