Pitching Inside is a major part of the game.
Young pitchers absolutely have a fear of hitting people, no doubt about it.
We have coaches calling pitches primarily away for fear of hitting people or leaving the ball out over the plate so a majority of FB's are called down and away. Compound that with the young hitters tendancy to want to pull everything and you have a ton of young pitchers staying down and away and not learning how to use both halves of the plate. IMO.
I believe you pitch inside to protect the outer half. You must pitch IN so you can pitch away. You are basically using your FB in to proctect your FB away.
I think of it like this.
If you and I ate dinner next to each other every night and you reached over and grabbed food off of my plate and I never did anything about it you would continue to reach over and grab food off of my plate.
Well one night you reach over and I stab your hand with a fork. You will now think twice before feeling comfortable enough to reach over and grab my food again. You are not going to feel comfortable just reaching over.
I think of it as the FB in is the fork and the outer half is my food. I'm going to protect the outer half. I need it to survive.
I think young pitchers must incorporate moving the FB to both halves on flat ground to a catcher and progress to doing it during sides and progress to doing it during games. The problem is the intensity ramps up as we move from flat ground to sideline to game so patience is a must. I feel that is how things progress and develop so that a kid eventually feels more comfortable getting the ball in to move feet etc...
Once they feel comfortable and attempt it in games they must learn to do it early in the game and provided the situation and count allow, they must move feet as soon as a hitter reaches out over the plate or takes a comfortable swing.
Side note: I feel the progression for young pitchers develping their FB should be in this order.
1. Learn how to pitch down in the strike zone. Down is a location too!
2. Learn how to use both halves.
3. Learn how pitch up. Mid belly and up out of zone.