[Brian Kopp DPM]

Well, until 1931, all Christians understood, from scripture and Natural Law, that contraception was inherently sinful.

Either all Christians up til 1931 misuderstood this issue, or many Christian since 1931 misunderstand this issue.

Because of the general apostasy of our times, I'm betting on the latter. An age in which the Christian churches are caving on every moral issue in compromising with the world is not likely one in which they better understand God's Will on contraception. On the contrary, compromise on contraception is of the same nature as compromise on abortion, homosexuality, divorce and remarriage, etc.

[count-your-change]

I don't know who speaks for “all Christians” or how they would be able to understand from Scripture an idea that wasn't there. Opinion, whether personal or institutional, is one thing, Scriptural teaching quite another as no support for objections to contraception can be found in the Scriptures.
If the question is misunderstood by someone it would behoove you to say how and why a large percentage of the population is engaging in what you call a “compromise” of the “ same nature as compromise on abortion, homosexuality, divorce and remarriage, etc”