It teaches basic basketball, and it is easy for first time players to grasp. MPRB PeeWees have to play a man. 11-12 year olds and up can play zone. The other thing I stress on defense is rebounding. Get position and jump high.
Defensive boards are the first step on offense, especially for the break.
To our advantage, many coaches do not stress rebounding on either end. When you look at the shooting percentage of 10 year olds, mostly what you get is rebounds. Limit your opponent's shots and get your 4 to make 1. On offensive boards I teach grabbing the ball with both hands, coming back down to the floor and going hard back up for a shot. No tip ins for 10 year olds.