The downmodding is for conflating grades with "deservedness" re: interning at your startup.

First, if someone does the work, they should get the pay/equity, regardless of age.

I say forget grades and jumping through other people's hoops. If he wants to do it, he will do it for its own sake.

Second, I'd let the poor kid hang out at my startup just to get away from his parents and structure. He can play with action figures or something. Of course maybe he's perfectly happy where he is, but if not, it would be nice to have someplace to go where the adults just leave you alone. A lot of us can relate to his situation.