Have some context - you are better off living in this time/place than any other time and your future children would probably be too.
That's just a logical argument, not whether or not you actually believe now is or isn't worth it. That's entirely subjective and not really worth arguing about IMO.
Human intellect is rare, and partly hereditary. Please pass your genes along - at least offer a sperm or egg donation.
I think that raising as many happy, healthy, intelligent and productive children as possible, with a suitable partner, is our very raison d'etre. Specifically for the high-IQ HN audience. Life and society becomes much simpler and more rewarding when you view things from this perspective.