That makes sense - but let me add that the idea that it is a myth that bedtimes must be enforced fits another observation: parents also seem to believe that they have to persuade or force their children to eat; yet in big families where no one can make sure everyone eats, all the children learn quickly to eat on their own.
parents also seem to believe that they have to persuade or force their children to eat
They do? I would be very surprised at parents who believed this. Eating satisfies a natural desire and feels good. Sleeping means stopping the fun thing you're doing and lying down in a dark room; why would kids want to do that?
Full essay: http://www.gwern.net/Melatonin