Because their parents are dingbats.
According to WebMD's general sleep guidelines, children ages 7 through 12 should sleep anywhere between 10 to 11 hours per day.
The new school year starts tomorrow, yet a lot of children in my neighborhood are out and about past 10 p.m. If those children goes to bed at 10:30 p.m., they'll only have slept for 8 hours if they wake up at 6:30 a.m.
Being sleep deprived 2 to 3 hours is a serious issue. According to Dr. Mercola, your reaction time slows, your cognition suffers, and your emotions are heightened when you lack sleep. What a fantastic way to start the new school year...
"How Much Sleep Do Children Need?" webmd.com Retrieved July 31, 2016.
"How Dangerous Is Sleep Deprivation, Really?" Dr. Joseph Mercola. Mercola.com. March 27, 2014. Retrieved July 31, 2016.