On the other hand, this protectiveness of our personal standard of parenting means that in order to enforce our standards, we must see the kids and people must defer to the parents for discipline. It almost means that because we don't allow others to impose their judgements on our kids, that they then impose their judgements on the parents.
The challenge is that, if someone sees behavior that isn't the norm in their experience, and that they personally consider (rightly or wrongly) to be insanely dangerous, what are they really to do? OK, they probably shouldn't raise a stink if some kid is riding a bike without a helmet. What if they're playing with firecrackers?
Unlike other places I've lived in, here there is a real fear that someone will dislike the way you raise your children and report you, creating much more serious problems for you than they might do elsewhere, at least not with the same ease.
I think it has a lot to do with what @stinkytaco said in his reply. It's a breakdown in communication and the same thing happens in other aspects of our lives, not just the child-rearing. I believe that this is what happens when there's so much emphasis on personal, individual freedom at the expense of larger communities those individuals form part of, all the way to the largest community -- the society itself.
It is {thing} the parent would never in a million years let their kids do (generally due to a perceived risk) and therefore other parents are actively endangering their kids if they let their kid do {thing}. Whether or not the risk exists and whether or not some small amount of risk is "better for the development of the child" (eg: independence/navigational skills developed by being able to walk to/from school unattended)
My own mother is one of those overprotective judging types. She'd never report to CPS unless it was clear-cut endangering the child (eg: physically beating them/doing hard drugs). But she still looks down on the neighbors for letting their kids play in the front lawn. The street being dangerous - kids should only play in the back yard! And only under adult supervision. My mother refuses to use a babysitter (even family) lest they let her children do something she would consider "too dangerous" or "stupid". I've gotten into a few arguments with her how I think that is doing more harm than good but they're not my kids so I don't have a say in it.
E:
And what CodeMage said. 100% agree there as well.
1. Mothers 2. Childless women 3. Fathers 4. Childless men
In other words, the ones who know the most about child rearing (in our culture, that is mothers), are the worst at assessing risk.
Leaving aside the dubious connection to knowledge about child rearing, including the suggestion that childless women have more knowledge than fathers on that point, "most prone to overestimate risks in low-risk situations" is not the same as "worst at assessing risk".
I suspect if a ranking was produced of those most likely to underestimate risk in high-risk situations, you'd get exactly the reverse ordering.
1) Mothers 2) Fathers 3) Childless women 4) Childless men
(Childless woman here, defending our honor)
IRL, anecdotally, I've found the opposite to be the case. It is almost always parents who feel something is wrong with the other person's parenting style.
I've also found it depends to be a culture desire to passive aggressively impose your will/lifestyle on other people.