abake
Rex Tremendae Majestatis
the Kryptonians like Jor-El, Kara, and the Council didn't care about genetic superiority, it was just the bloodlines they cared about. Back thousands of years ago they decided whoever was a leader, a worker, a soldier, a teacher, whatever their bloodlines were back then, their bloodline would always be those types of people. So when they created this Codex, it was flawed because whose to say those bloodlines were the best for those positions in their society. Jor-El realized this but it was too late. Zod also realized this, but he is the one who wanted genetic superiority. Only the best bloodlines should be preserved was his belief and his followers.
I thought they said "centuries".