The Dutch are by enlarge fitter, more progressive in many aspects of their social structure, are at least as well educated as the Australian population, and use bicycles as a population exponentially more than Australians and have the choice as to whether they to wear a helmet or not.
Personally I've worn out half a dozen Bicycles over the last forty years. On this topic I go Dutch. If I want to go and get the milk at ambilitory speed down a disused foot path surrounded by deserted roads at seven o'clock on a saturday morning and be fined, $200 dollars for that behavior, i'll know the nazi's have taken over. If I'm going to rocket down an arterial road in peak hour and not wear a helmet, i'd be a bloody idiot, and deserve to end up under a cement truck. But treat people like children and they behave like them.
Not only that hardly a day goes by, if you bother to look, that this law goes ignored and un-enforced, that by definition makes it a bad law.
A lot of people went along with the Vietnam war because the government decided it was good policy, until enough people (radicals, to start with) revolted, it will be a long while before the brain damage done to discerning bicycle riders allowed to make their own choice catches up with the damage done by that policy decision.
Happy being fat? Happy being lazy? Happy with compulsory helmet laws because it gives an excuse not to get on a bike, ever....