What I never understood is how remaining a child physically for years and years means you remain a child mentally. Doesn't years of experience add up over time? Wouldn't you grow in understanding and capability just from practice at taking care of your food needs? Just because you are a child doesn't mean you can't learn how to plant and fish, given time.
Given how the virus seems to drive you crazy while it's killing you, perhaps a side-effect was that it kept the children mentally as children and any that began to mature would go crazy instead of maturing?