confused?

[gina]

What im rlly confused is why did the people out side the fance creat them ? make there city .??

[Kristen]

There will be spoilers in this.


If you give this too much thought, you will always wind up confused because the author left gaping holes in the plot.
Buuut, the idea in creating the city was to breed divergence or "genetically pure" people to fix all the problems in the world that they blamed on people being "genetically damaged."