I think that 10pm in winter is derived from the following. Child comes home at 10pm, it might take an hour to get ready for bed, then you get 8 hours of sleep before you wake up at 7am for school at 8am.
It just says "children age 12 and younger may not be outside after 20:00 unless accompanied by an adult. Children ages 13 to 16 may not be outside after 22:00 unless they're returning home after an approved school-, athletic-, or youth-program function. Between may first and september first children may stay out an additional two hours"
Even though it's not stated the "accompanied by an adult" applies to ages 13 through 16 as well.
No I'm not asking for the law to be subtle. I'm asking for the law to not put its nose into things it has no business doing so.