If you argue that all this applies only after the long exile and punishment – this is precisely what proves the point. For if so, we see that the Supreme Will ensures that eventually everyone benefits. From this we may infer that His will is only to benefit, quite literally. However, He has to deal with each one suitably according to his nature.
It is necessary to punish the wicked in order to forgive them afterwards. If the intention was to reject the wicked, they should literally be destroyed instead of being punished in order to benefit them afterwards. The fact that they are punished to benefit them later is clear proof that His will is only for good. For the intended result of an action is the ultimate purpose that governs all parts of that action.
In the end, all men, whether righteous or wicked, receive goodness. If so, the ultimate purpose is to bestow goodness on all. This proves that His will is only for good.