There has to be some "givemes" when you're watching a movie, especially sci-fi movie. When someone says "the air is breatheable take off your helmets". You can't think OMG that's so stupid!, no you have to think, this is a movie, i don't think anyone wants to watch 6 bubble heads penguin about and i can't tell who is talking. This is why when RDJ is in the ironman suit, you get the in your face reality tv camera.
That's reason enough just to drop that one talking point... it's a movie.
BUt also since it is a movie, we have to take a cabin in the woods look at it as well. Joss whedon basically made a silly movie, outlining the "formula" for a horror movie, remote location, nothing to do, stuff and coincidence plays a big part, and you have the fool, virgin, whore, athlete, scholar. Play a bit of monkey throwing darts at a scenerio and you have a horror movie.
Pretty sure the same could be said about sci-fi movies, especially aliens, I like most am a child of the 80's so aliens is my scariest and most watched movie in my life. So maybe there's some nostalgia that we're all trying to fight when watchingprometheus. but someone go break down the sci-fi formula, i gotta go get the family breakfast...
i guess it's , humans are intrigued, make a boo-boo on first contact (hello facehugger), ppl revert to their primal natures (scared, immobile, commanding) and loose their shit, with the duty bound captain, fascinated scientist, red shirt helmsman, man/woman with a purpose, smart lower class/rank (maintainance/janitor) guy that knows whats going on and what to do but no one listens and dies second that prompts the systematic culling. (argh typed quickly gotta go buy food)