They managed to downplay the kid-on-kid violence in the Hunger Games. I’m sure they can do so on Enders Game.
It’s the latest fantasy craze and I personally don’t care for it. Ender’s Game still is relatively underground but has a hardcore following. I think sci-fi is generally more abstract than fantasy so that may have something to do with it.
And another thing, the violence is also something that helps shape and strengthen the character. It can’t just be left out.