I think all notions of child rearing from Dr. Spock are suspect. I wonder where he got his ideas from, Freud and psychoanalysis? I'll try to Google. Later
Brazelton was one such irritating, mawkish, crooning media advice-doc. Then he was overheard to admit he'd never spent more than fifteen minutes at a time with a child. He was too busy giving advice...
Pediatricians don't raise children. Their wives and nannies raise their children. (Nannies if the doc is female). Pediatricians should stick to attending to children's physical ailments which can be treated clinically, not pretending to be Wise Nanny-Man.
I don't know who is the "Wise Man" for people looking for guidance...but I know that Pediatricians are no wiser than anyone else. Probably less wise than many.
I do know that children used to be toilet-trained a lot earlier than they are now.