Here's one candidate. Maybe your child's brain was designed by natural selection over millions of years during which mothers slept with their babies. Maybe the young brain is designed to respond to this situation by screaming frantically so that any relatives within earshot will discover the child. Maybe, in short, the reason that kids left alone sound terrified is that kids left alone naturally get terrified. Just a theory.
Humans are resilient, by design.
Presumably most breast-feeding benefits can be delivered via daytime nursing. Still, we certainly don't know that an 11-hour nightly gap in the feeding schedule isn't doing harm. Meanwhile, as all available evidence suggests that nighttime feeding is natural, Ferber asserts the opposite. For a while doctors said mothers shouldn't feed more than once every four hours. Now they admit they were wrong.