It’s true that many couples have fewer children, or none, because nature worked out that way. However, for those who are naturally more fertile, the pressure is always against having another child. You’re destroying the environment, you’re crowding the schools, you’re dividing your resources and all your kids will be Failures, your 15-passenger van is hard to park, yadda yadda.
It comes down, in my opinion, to a visceral, rather than rational, concept that there’s just something *gross* about the fact that sex makes babies. Like the idea that humans should really be past something so primitive and *ick* biological.
This reminds me of some article years ago in which a homosexual man was arguing that arranging for a child through surrogacy was more advanced and "evolved" and a man and a woman conceiving a child together the natural way was "practically prehistoric."
It's interesting that the sodomites find natural relations between a man and a woman so deeply repulsive, no?