Hardly too much FMJ. I've seen the movie once.
Yes, if a recruit strikes out for being yelled at, he gets booted... that doesn't help the problem. The recruit wants to stay so he will not react to being yelled at in any violent manner... he's not going to hit the drill sergeant or tell him to screw himself. So he'd be more likely to react violently in situations where he can do so - maybe being brutal to civilians or prisoners of war, maybe just being too trigger-happy in combat.
This is, of course, entirely speculative on my behalf. I am no master of human psychology, and I am certainly no soldier.