Dunno if this is still necessary, especially in this topic but:
SPOILERS!
I think there's definitely something to the movie. There's some strangeness to the plot, but most of it seems to be unanswered rather than inconsistent. Well... except the cave drawings, ie "How did they get coordinates to that system if the Engineers only visited the once millenia before humans existed, and didn't seem to really care about them" (IE "would you give an insect the map to your home?") but that could also just be an unanswered question. I'm wholly open to there being multiple factions within the Engineers' civilization.
I really have two main theories about the movie though.
1) This is the movie Scott wanted to make when he made Alien. Which really means Prometheus is his Episode 1, which considering how that turned out, isn't that bad really ("Movie Spanning Pod Race" trumps "Rolling Space Ship" on the scale of terrible ideas). There's a lot to support this, with multiple scenes, ideas and images taken directly from the original plans for Alien. It's a bad thing because without all of that extra stuff Alien was a really good Science Fiction and Horror movie and it stuck to a single idea throughout really well.
The horror came from not seeing the monster and it's graphic depictions of male-rape. Prometheus tries to bring a lot of existential horror to the equations along with dozens and even hundreds of different themes throughout the entire movie, and because everyone has their own agenda it tries to directly address all of them. I know that's a good thing from a narrative angle, but not in movies. What it is good in directly leads us to #2
2) It's a movie based on a novel that was never written. If you think about it, every single person named within the movie has a direction and motive for the expedition. In most movies this means three to four people with different outlooks on the situation, in Prometheus this meant 6-12 people. That's not the kind of thing you try to toss into a feature length movie. It's the kind of complexity that works really well within a novel. On top of that you have many important ideas being tossed around and they're happening so fast that you don't have time to process them.
"The murals are changing.." Oops, we're only going to show you half a second of that, but since you only saw a single second of it anyways, it's not going to matter.
That's the kind of thing that requires descriptions and written words to convey. Three seconds of film just makes it meaningless to the moviegoers. It keeps happening too; the alien head, the worms in the ground that were touched by the ooze, David talking to the Engineer. It's all information that happens incredibly quickly but is important to the narrative. Spread it out and write it down and you have an excellent science fiction novel. Compact it in and film it and you have Prometheus.
I didn't find any single thing I objected to in the movie, but when you put it all together it's just a bit of a mess.
Ridley Scott also broke one of the cardinal rules of film making. You can make a bad movie and fans will forget it, but if you make a disappointing movie fans will never let you live it down.
