The same thing made me roll my eyes in Avatar: the science is sophisticated enough for interplanetary travel and the building of avatars, but they can't fix a guy's spine? Cripes, we're about 50 years away from doing that now.
Actually, they were pretty clear in Avatar that they could fix his back. That's the incentive they offer him to do the job - you'll get your own legs back kid.
It's implied that it's too expensive. Somehow cheaper to fly him to Pandora, so still damn silly.
That's coming back to me now. At the time, I still objected to them NOT fixing the guy's spine for the reasons you mentioned. Also, I don't recall, but if the injury was related to his military duty (as opposed to, say, a car accident) it seems ludicrous that they would use the expense as an excuse NOT to fix him -- unless there was sort of conspiracy behind it: set him up with an "accident" but only heal him if he does this favor for them. I found
Avatar pretty forgettable either way.
I was discussing
Prometheus with friends today, and the longer we talked, the more I hated it. I went from disappointment to hatred in about 20 minutes. Overall, the movie is a big "F you" to people who are
ALIEN fans: we're finally gonna show you the Space Jockey's back story, but not the one from 1979! Oh, and here's the origin of the aliens... but not really! Come back for the sequel in 3 years, suckers!!
Maybe we'll fill in the blanks at that time...