Where is the Church’s Compassion?

From the website, Catholic Answers, comes the following:

In 1968, Pope Paul VI issued his landmark encyclical letter Humanae Vitae (Latin, "Human Life"), which reemphasized the Church’s constant teaching that it is always intrinsically wrong to use contraception to prevent new human beings from coming into existence.

Contraception is "any action which, either in anticipation of the conjugal act [sexual intercourse], or in its accomplishment, or in the development of its natural consequences, proposes, whether as an end or as a means, to render procreation impossible" (Humanae Vitae 14). This includes sterilization, condoms and other barrier methods, spermicides, coitus interruptus(withdrawal method), the Pill, and all other such methods.

Of course the site backs this up by Scriptural references:

The Bible mentions at least one form of contraception specifically and condemns it. Coitus interruptus, was used by Onan to avoid fulfilling his duty according to the ancient Jewish law of fathering children for one’s dead brother. "Judah said to Onan, ‘Go in to your brother’s wife, and perform the duty of a brother-in-law to her, and raise up offspring for your brother.’ But Onan knew that the offspring would not be his; so when he went in to his brother’s wife he spilled the semen on the ground, lest he should give offspring to his brother. And what he did was displeasing in the sight of the Lord, and he slew him also" (Gen. 38:8–10).

The biblical penalty for not giving your brother’s widow children was public humiliation, not death (Deut. 25:7–10). But Onan received death as punishment for his crime. This means his crime was more than simply not fulfilling the duty of a brother-in-law. He lost his life because he violated natural law, as Jewish and Christian commentators have always understood. For this reason, certain forms of contraception have historically been known as "Onanism," after the man who practiced it, just as homosexuality has historically been known as "Sodomy," after the men of Sodom, who practiced that vice (cf. Gen. 19).

Uh, that’s it.  Onan deliberately defies God and is killed.  Perhaps the reason he was killed was because he disobeyed God, not specifically because he “spilled his seed”.  I don’t see how you can go from this one instance of coitus interruptus to a broad prohibition against contraception in general.

So under any and all circumstances, contraception should never be used – never.  So, apparently, if your spouse has a sexually transmitted disease, you should either never have sex again or risk getting the disease as well as potentially passing it on to a child.  If you already have as many children as you can afford to raise properly with adequate food and clothing, then again you should simply stop having sex or get a second job to pay for another child.  Of course all this extra work would leave you little time to spend with the new child, but that appears not to be a concern.  If your wife has some medical condition that would make childbirth a fatal proposition for her, well, too bad – no sex for you, or you could go ahead and have sex and potentially kill your wife.

These are just a few instances where contraception would be a vital part of a healthy marriage, I’m sure there are others as well.   Risk disease, death, and poverty or simply don’t have sex – some choice.  Where is the Church's compassion?