Here's the real reason child-rearing is so difficult: only people are allowed to do it. If we could find some flawless proxy to stand in for us, this whole thing would be a lot easier.
You and I are given a certain number of shortcomings; both by our wiring, and by our upbringing. The very instant we bear children, we obligate ourselves to the task of training another individual how to overcome those very failings. Frankly, I haven't quite figured out how to overcome them in my own life. And what's worse, is that: 1. The children don't want their flaws corrected, and 2: every flaw we see in them screams about our own failings.
So here's how it works: Your children screw up. You see yourself in their screw-ups. Your parents laugh. You yell at your kids out of fear that they will be screwed up by their parents the same way that you were. Your parents laugh again. Your kids resent your "training." You get together with everybody at Thanksgiving and apologize to your parents.
Maybe we could just all rear someone else's children.
