Sounds like a terrible childhood.
The years I had in an all-boys prep school were easily the best years of my childhood.
Well, except if the alternative was going home to an empty house and hanging out with a gang while your "single" parent mom doesn't know how to discipline you, or keep you out of a gang.
The regimen is not all school, it's mentoring, field trips. I think the plan of the extended hours is to keep them for as long as they can under a "good" influence and caring atmosphere, instead of sending them home to hang out in the "hood."