I wasn't intending to be condescending. More like tongue in cheek. I'm American. I'm aware that Americans look at how the Netherlands does it and we go "That doesn't make sense! That is terrible! etc."
I'm not saying they never get hurt. I don't have studies and articles at my fingertips, but from what I have read, the decision to not require a helmet is part of what makes cycling popular in the Netherlands. From what I understand, studies show that requiring a helmet reduces the adoption of bicycles as a mode of transit. My recollection is that they decided they wanted bike-friendly cities in part because too many children were being hit by cars.
There is a concept called "lying with statistics." When you cherry pick a single data point to support your conclusion and how you think things should be done, sure, you can make it sound like you are clearly right and this is crazy. You can do that on just about any subject.
There are other ways to look at this problem, such as:
1. How many more serious injuries and deaths are prevented by having a bike culture instead of a car culture?
If the answer is you have fewer injuries overall and they are less serious, then accepting the injuries from bicycling makes sense. My understanding is this is what the Dutch found to be true.
2. How much measurable benefit does society get by creating a society where women, poor people, children, etc can still get around?
In some parts of the US, it's nigh impossible to get a job at all if you don't have a car. No one wants to hire you. Public transit is too bad, so they assume you can't get to work reliably. This becomes a poverty trap. You can't buy a car because you don't have a job. You can't get a job because you don't have a car.
Poverty traps foment crime, cause minor health problems to balloon up into expensive major health problems, etc. There are myriad ways that preventing people from getting around unless it is some optimal means to get around can negatively impact society more than just letting them take a few risks on their own recognizance.
I'm not going to look up the articles, studies and data. I'm an American who has lived without a car for more than a decade. I wanted to be an urban planner before life got in the way. Reading stuff about how to get people to walk and bike more is something of a hobby of mine and the Netherlands is generally held up as a gold standard.
I was just trying to give you the nutshell version of what I know while feeling like it was probably pointless because it probably doesn't matter how well I say it or how much evidence there is, American prejudice looks at those pictures of both adults and children riding around without a helmet and goes "Nope!!!!!! That's wrong and bad and terrible and evil!"
The same Americans who say that about bicycle culture in the Netherlands will be all "Meh. Accidents happen." if you try to argue that car culture is maiming and murdering people on a daily basis here in the US and we desperately need to do something about it.
(Yes, I'm aware you may not actually be American.)