We are fascist parents (spending a lot of time teaching over tired children ...)
YANBU
We send 12 yo dc up to bed at 8pm and expect her to be resting/asleep/in bed by 8.30pm. No TV, video or computer in room, occasionally dc has a sneaky read, but we try to encourage reading before bedtime. If dc doesn't get this much sleep dc doesn't focus well and looks awful/exhausted.
Bit more relaxed in the hols especially when abroad, but pull in the bedtimes 5 days before school starts and don't usually stretch out the bedtimes beyond 10ish.
DC only got bedtime stretched to this hour (8.30) when she went to secondary school, before that it was lights out at 8pm when she was 10+ and even earlier before that.
It's a personal choice as a parent. This works for us as a family and dc as a child. DC does complain (but my friends blah, blah, blah) but at the end of the day that's their parents' choice.
Do what works for you whatever that may be (everyone)