From the article linked.
"Craig's first objection to probabilistic arguments from evil is that the probability of known facts about evil on theism is inscrutable (unknowable):
"1. We are not in a good position to assess the probability of whether God has morally sufficient reasons for the evils that occur.
God is said to be simple, that is God's goodness is part of his nature. Simplicty is mean to side step the issue of are there any outside forces that limit God. This avoids the issues of where God's attributes come from and how they came to be attributes of God. There is nothing beyond and outside of God metaphorically. No metaphysical necessities or laws or rules outside of God that God must obey.
Descartes,in his letters to Messennes takes this ti its logical conclusion. God creates all the laws and rules of the Universe, the Universe's logic and all metaphysical necessities of the Universe that are not God. If so, God can make any rule God wants the Universe to have. Thus God can arbitrarily rule out say, all moral evil. he could create man with a perfectly good nature as God enjoys, and free will to freely follow his good nature unerringly, again, as God enjoys.
Thus God has no possible obstructions that could make it impossible to create a Universe without moral evil. Since he makes all the rules, God can have a perfect Universe. Thus WCL's question is answered. There is no issue of inscrutability involved. The idea that we must have evil to obtain a greater good is an invalid proposition.
I call this the argument from super omnipotence. God being able to create any state of affairs God wishes, and God being supremely good, is quite capable of banishing moral evil all together, and any theory as to why he cannot is not viable.
Descarte's idea can be derived from the doctrine of God's simplicity and either must be accepted, or it destroys God's simplicity and implies a whole world of metaphysical necessities outside of God that limits God's omnipotence. But if we accept that God is super omnipotence, and perfectly good,we have evidnce that God cannot exist. We would live in a far different Universe than we do.
William C.Barwell