Every once in a while I will stumble across another this-baby-management-book vs. that-baby-management-book argument. And they all can cite statistics and studies and personal examples about how this book works and that book doesn't. But hardly ever do they seem to get the point.
Every baby is different. Every mom is different. Some moms freak out every time their child cries and need to be reassured that they aren't going to be warped for life because they had to wait a couple of minutes. Some moms think life can be scheduled to the minute for the next five years and need to learn to relax and go with the flow a little more. Some moms (like me) have their heads so lost in the clouds they need a lot of routine or they draw a blank as to what, exactly, might be a good idea to try next. (Diaper change? She needs a diaper change? Oh, yeah, it has been five hours, hasn't it?)
Some babies need to eat every two hours around the clock for months. On the other hand, I met one mother who had one baby (out of eight) sleep for 10 hours a night starting at birth. I'm sure no one would advocate that as a standard for any other baby, but he survived just fine. Some moms have to nurse frequently or they lose their milk supply. Some moms have milk for years after weaning. Some moms really need uninterrupted sleep at night. Some are going to have it more interrupted by not nursing than by nursing.
Not that books can't have good ideas, and some have more good ideas than others. I like my mother-in-law's standard advice: "Look at all the books. Then look at your baby." If you're putting books above your baby's health or long-term happiness, then you have a problem. Otherwise, why worry?
If someone reports that they and their baby are happy under Plan Y, why do some people feel a need to go around telling them Plan Y is evil and dangerous?