I've just come back from seeing Prometheus and I'm afraid to say that I actually quite liked it. Sure there were the inevitable scientific errors, but what can one expect from Hollywood (a recent interview about the Minority Report think-tank pointed out how surprised that scientists found that movie makers would want to talk to them - and how surprised the movie makers were that scientist would want to talk to them), and someone obviously decided that turning the melodrama dial to "11" wasn't enough (and pencilled in a "12" so that people could start panicking before there was anything to panic about), but as an exercise in world-building (which is one of the things I liked about science-fiction) it all hung together quite nicely.
The problem is science generally makes a lousy film, so it was necessary to get people to react contrary to their natural trained inclinations in order to get some essential conflict into the storyline (so as to develop "character"), but all that did was make people accustomed to such technical roles scoff at the lack of professionalism and thereby snap their disbelief suspenders. So you basically end up not emotionally investing in the film. And if you are that theoretical everyman (or everywoman) without the sort of professional training or exposure to such people, then you don't really have enough knowledge of their normal day-to-day life to emotionally invest in the characters either.