Well, there are two different kinds of middle-schoolers, young teenagers.
There is the kind OBSESSED with D&D . . . they figure it out, even if they get it wrong at first. That was probably most of us when we were kids. I was super confused with the Basic boxed set and the Advanced hardcovers . . . didn't figure out they were two DIFFERENT GAMES until high school . . .
Then there are the kids who really want to play, but can't be bothered with that college textbook sized rulebook of a PHB. Yet, they want all the options available . . . . and not even adults read the DMG . . .
If you are teaching a small group of kids to play and you can get them to patiently work with you . . . sure! But I'm working with an afterschool group of over 20 with just me . . . . hoo-boy, its an experience!