Maybe all those other babies are also incredibly healthy and happy, or maybe not - it doesn't matter. They don't sleep through the night, and neither do their parents. That makes parents cranky. When I don't get enough sleep, I get cranky, and there is no way that anybody gets enough sleep getting up every two hours to feed a baby. Cranky parents make different decisions than happy parents.
Babies respond to the emotions of their parents.
Of course, it works out like most things do, and many of these babies will grow up to be healthy and happy and perfectly normal functioning adults in our society, and the parents will recover. By the way, those experts that told us that we would never be able to get our baby to sleep through the night are now starting to mock us for our decision to start our baby's semi-formal education within two months of birth. I don't agree with everything in the book, but I like the general outline and ideas that he provides. In fact, there are many things I don't agree with in the book, but it is still a good resource. His rationale is that oxygen is required for conscious thought and babies don't breathe in the womb, therefore babies don't have conscious thoughts.