Prometheus is gorgeous, but the designs are uninspired. The film is replete with fantastic actors (especially Fassbender) who are serviced not at all by the wooden, miserable script. If the movie were merely a heavily flawed auteur effort I would cut it more slack, but the naked desire to turn this into a franchise puts that idea away.

That last sentence also brought me to another thing that pleases me: I was always wondering during the Alien movies what kind of bizarre evolution would have led to the alien species, and this movie gave the perfect answer: They were simply artificially developed as monstrous bioweapons, by the masters of such bioengineering.
I don't mean to be insulting but you're kind of stupid for not understanding this the very first time you watched "Alien". It was always very evident that the Space Jockey was hoisted by his own petard, so to speak.