There's nature and nurture and regardless of where the lines fall, the implication from idiocracy is the morons cannot adequately nurture any positive genetic intellectual variance. If they can't nurture it, it doesn't really become an advantage. I'm fully convinced we've lost numerous genius individuals all capable of changing the world because their entire life was spent in a rice field or similar setting. What would Einstein have achieved if he hadn't had an electrical engineer as a father who helped unlock his fascination with the world? I have no idea.