Just this evening, I stopped at the grocery store on my way home from work. My two-year-old was buckled into his car seat next to me. No, I didn't leave him in the car while I went shopping, but after we got back out to the car, I buckled him into his seat, loaded up the groceries, and left him alone, for a good 15 seconds, while I took the cart to the cart return! Was he in danger? No. He was never out of my sight. But he was alone in the car. With a little imagination, I'm sure you can devise a scenario (no doubt, a rather improbable emergency) in which the best thing to do for your child is to leave him alone for an extended period.
For shorter periods, it's easier. You're going on a brief excursion, to take books back to the library, let's say. You'll be gone about half an hour. The baby's asleep in his crib. Should you wake up the baby, strap him into his seat, and cart him along? Or should you let him sleep? The common "wisdom" is that it's too dangerous to leave the baby alone. I question this. What's the chance that you'll be involved in a collision on your trip, one that would injure the child? Small, but statistically significant. What's the chance of his being injured at home? Not zero, but surely much less than that of a car crash.
What's my point? Should infants be left, routinely, to fend for themselves? No, of course not. My point is that each parent should be able to judge for himself what the best course of action is, given his unique circumstances. Of course, he can't. If a parent's judgement conflicts with the State-approved "wisdom", and he's caught, the agents of the State will come and kidnap his children at gunpoint.
What's my point? That parents are, almost always, the best judge of how to raise their children; the government has no right to interfere.
Dissolve those agencies that do so!