Yup, there's ginormous status quo bias going on here. If we lived in a world stretched to the limit for resources, where policy is impossible because everyone is a bigoted moral fossil and the few sane leaders left have no clue what they're doing because it's all so new, and you proposed "Hey, I know! Let's kill everyone over 80!"... everyone would just stare and ask "Have you been reading Pebble in the sky again?".