My parents always sent me to bed at 9pm, whether I liked it or not, and I turned out fine.

I think this idea can be summarised as "Adults know better than children what is best for them"? That message is completely counter to TCS philosophy.

I assume instead that children will work out how best to live in society, with parents offering guidance where tolerated. What are the alternatives? That a child is incapable of learning how to interact successfully with the world around him unless someone forces them to? Or that a child must be forced to comply with societal norms because they won't see them as worth while in their own right. Child as stupid? Child as wrong headed? Child as insufficiently provided with information? (then provide the information for them to make their own reasoned decisions, don't keep making the decisions on their behalf!!)

One cannot assume that all children of certain ages need the same amount of sleep. Or even that the same child will always need the same amount of sleep - it's going to depend on what sort of day they've had. In fact, the only person with sufficient information to know that a child needs to go to sleep is that child themself, and the very best gift their parents can give them is to read their own cues of tiredness. And you don't do that by overriding those cues and sending someone to bed at your own parental convenience.

The lucky children have parents who have let them sleep whenever they want from a very young age. When tired, they lie down and go to sleep. Those parents who have forced bedtimes over the years have to step back at some point in order for their children to learn for themselves what their cues are. And parents can do that stepping back when their children leave home, perhaps to go to college. That's the classic where students stay up really late and miss classes, not because they don't want to be at the classes ,but because this, aged 19, is the first time in their entire life when the only thing telling them to go to bed is their own cues of tiredness, and they are having to learn to read those cues. The bedtime imposing parents have done a pretty rubbish preparation for life course for their children there, wouldn't you say?

The "you have to go to bed because you have to get up for school" argument doesn't wash. If one's own activities at home in the evening are much more interesting and engrossing than school, then it should be a question of finding ways not to have to go to school, or not to have to go to school full time, rather than curtailing those activities. It is quite common, I believe, for children of TCS families not to go to school - because so much learning on someone else's agenda is simply not effective or efficient. And there is no freedom of association in a school. If there are better things to do tonight than go to school tomorrow, then the problem to solve is how to get your parents to allow you to be home educated, not how to motivate yourself to get into bed and shut your eyes.

"I turned out fine" boils down to "I was coerced and it never did me any harm", which is the same in spirit, though of course not in seriousness, as "my father beat me with a belt strap every Friday night and I turned out ok". It's not a question of "how much can we coerce our children and still have them turn out ok?". It's a question of "what is the morally right way to interact with our children?". Respecting their wishes about when to go to bed, and taking them as seriously as our own, is a good starting point.

It all comes down to parental limits, with bed time as one of the classic boundaries not-to-be-pushed. But parental "limits" are parental blind spots, where there is no acknowledgement of parental fallibility, and are thus inimical to consentual family living.