With opinions, be conciliatory if you wish, but it's fine to be firm about facts. Remember, reality is ruthless. People do need to eat and our nature is to get as much to eat as possible with the least amount of effort. Some call that efficiency and the most efficient way of getting food is by interacting with many others using the miracle of money. Are there any really hungry people anymore? In today's modern world, do parents still need children to help them in their old age? Is getting married a private decision? Do older people still live off younger people's work? Is the decision of whether to create a child purely personal? What happens to you if many in your town stop reproducing? Can immigrants replace the people not being born? Are childless retirees living off other people who did raise families? What government can do about declining population.