I'm not sure you'd even have to get into human evil, and whose "job" it is to control it. You could simply ask, why would a loving, caring, omnipotent god allow tsunamis and earthquakes and hurricanes? Obviously those cause untold misery, probably at least as much as that caused by human evil, but they're "acts of God."
If there's an omnipotent god, and that God is also "loving and caring," then either God's definition of loving and caring, or God's ultimate loving and caring purposes, are so far beyond our understanding that there's hardly any point in trying to grasp God's intentions.
All humans share some basic moral assumptions, whether they follow them or not. But it's clear that our moral assumptions in no way match the way the world operates, even in its "natural" state, that is, without human intervention. Since God, if there is a god, is presumably in charge of nature, then one has to ask why God's morality seems so out of sync with ours.