Just clicked for me that this movie is so implausible and contrived....
I think it was when Dave explains the whole pure and damaged thing to the MC (I don't remember her name and I don't really care) and explains why she's just the specialest little snowflake ever that I began to question just how contrived this entire scenario is.
To begin with, regardless of how society develops, you'll NEVER convince folks to be okay with creating this experimental society out in the middle of nowhere in some idiotic attempt to purify the human genome when you have no reason to believe it'll happen anyway. Aside from getting public approval, who'd fund this ridiculous experiment? Have trees been engineered to grow money?
And the reaction of the people to the coming of...what, the chosen one? Everyone's excited at the coming of what essentially amounts to a reality tv show reject.
I know that if you look at it like this, many movies and stories appear contrived but....the very reasoning behind the creation of this experimental colony just seems like so much quackery. You can sell this idea in novel form because YA novels are expected to have some weird nonsense in it and to many consumers they're consigned to a dark part of bookshops and libraries, but when a movie gets a good enough budget to afford THESE kinds of effects (seriously, the special effects were brilliant) it's something that can be made front and center because you can SEE what the movie looks like visually (it's not easy showing folks what's contained in the pages of a book other than to give you excerpts and plot summaries, but with a movie you can actually SHOW what the movie looks like).
The movie is visually appealing but the story is so contrived....