Its incredibly unrealistic to expect that people will avoid intercourse if they dont want children.
Whenever I see someone apparently get more worked up about the use of birth control than they do about abortion, I get the impression that they care more about people engaging in intercourse without intent of pregnancy than they do about whether someone kills a baby.
I agree. Completely.
Killing a baby is murder, and by the parents.
Its Biblically horrendous.
There is another issue. and It is related. In fact, the theologians prove that it is causative.
Read Humanae vitae
http://www.vatican.va/holy_father/paul_vi/encyclicals/documents/hf_p-vi_enc_25071968_humanae-vitae_en.html
Just read it.
Now. To your point. The point people in this failing culture make, especially from the liberal point of view:
Its incredibly unrealistic to expect that people will avoid intercourse if they dont want children.
Please, and very very simply, prove your point, and also tell us how We, in this time, from 50 years ago, are so correct, in our sudden dependence on the pharmaceutical industry for the first time in human history, that we are the only ones since the year 3500 BC who separate sex form birth, and marriage from sex?