What made this such a travesty was that it was an act of immense pride on King David's part. Not just the pride of a self-inflated ego, but of usurping Divine sovereignty and province. In taking a census, David was arrogating to himself an authority that belongs to God alone, an authority over human life.
From the beginning, God has given to man dominion and authority over all other life on this Earth - over all the animals and plants. This authority is explicitly given in two places: to Adam & Eve in Gen. 1:26-30, and again to Noah after the flood in Gen. 9:1-3. Two things are noteworthy here. Both passages include the command to "be fruitful and multiply", and neither passage grants man authority over himself.
Human life belongs exclusively to God. Murder is a crime against a human victim. But even more, it involves a sin against God's sovereign authority over the victim's human life. Suicide is a similar sin, since no man owns his own life; it belongs by right to God alone. And so the crime of population control is likewise a sin of unmitigated arrogance, of assuming control over human life itself.
Two posts ago, I asked who or what ought to be controlling human population. Individual families? Governments? A world government? A population control agency? The answer, from the above, is: God alone.
Which leads to one more question. Why do Bill Gates and Warren Buffett and Planned Parenthood and UNFPA and other rich and powerful folks clamor for world population control measures? Is it pride? Is it hatred of God and of His sovereign claims? Is it fear of some calamity resulting some day, somehow, from (gasp!) Too Many People? Is it, perhaps, fear or loathing of the people themselves, and of demographic threats to their affluence?