It is definitely an uphill battle to preach this course of action. It's not as if it's a matter of changing some routine such as spraying aerosol deodorant on yourself or throwing away glass bottles. There is a very strongly ingrained drive to have children. She also gave us the instinct to care for and nurture the young. Aggression kept us alive when we had to struggle to survive, but if I killed every person that cut me off in traffic, I'd be in serious trouble.
Aggression is often seen as being 'bad', so it's easier to discuss controlling it.
Having babies, on the other hand, is definitely regarded as a blessing by almost everyone. The difference between a child and an SUV is that the child is a living creature deserving as much love and happiness as any of the Lady's children. Regardless of the manner in which they were brought into the world, we must make sure each one is fed, housed, and cherished. This would be helped by each person having adequate access to a variety of methods of birth control, including abortion. The language reflects the attitudes of society, which generally views childlessness as abnormal and suspicious.