Why do you think this is?
I would have wanted my parents to be psychologists or doctors or teachers,at least they would have had some knowledge about emotions and how to treat people not only the defective upbringing they'd had in that field.
At least then I wouldn't have felt like a total alien, and feeling guilty because hey, it's not my parents' fault they thought shaming a child a lot is good, because they'd never been taught.They just did their best. So I can't blame them.
But if you are a psyhologist then you've learned what emotions are, what validation is, so it's your fault if you were shaming your child or similar.

Also maybe those parents you've mentioned would not get a medal for parenting or could be very selfish but at least they would talk about emotions wth the child. Because it would be natural to them. So the child would learn that.