Think about it:
If Dr. A writes a book on parenting and Dr. B writes a book on parenting and Dr. C writes a book on parenting and Dr. D writes a book on parenting... if they all give you different information and have different ideas, how do you know which one is "right?"
I'm sure every parent that loves their child and wants the best for them has ideas on how to be the perfect parents and raise the perfect child. You can ask my parents: I was NOT the perfect child. Does that mean they were bad parents? No, it means I made poor choices and was a weeeeeeee bit rebellious. But guess what, I think I turned out pretty dang good in the end.
We can guide our children in the right direction, we can nurture them and provide for them, but we can't hold their hands through life and expect them to be perfect. What one quack says today can be completely different that what another quack says tomorrow.
I think good parenting is instinctual and involves a person's morals and values. If you teach your children good morals/values and lead by example, I'm pretty sure it will bring about better adults in the future. I'm sure there is a happy medium between being a drill sergeant Nazi and being a yeller and a spanker who lets their kids do anything they want and buy them everything they want.
So far I think my kids are pretty good, but I know I'm not perfect and I know they aren't. I just know that I don't need some flavor of the week Duck telling me how to raise my child!
Put that in your pipe and smoke it. :)