The issue with me isn't HIM not killing anyone, it's the fact that he refuses to let anyone ELSE kill anyone.
For example, when Scar was fighting the Crimson Alchemist, Al created a rock hand that trapped the Crimson Alchemist in it.
The Crimson Alchemist had just went through the streets of Liore killing every innocent he could. If he was let go, he would continue killing innocents until someone killed him. So, now he is defenseless and Scar prepares to finish him, but Al gets in the way and stops him from doing so.
This resulted into Al being turned into a bomb, and costing Scar his arms, something that would eventually lead to his death.