All people are evil
It is good that evil people are punished.
Evil people must exist in order to be punished.
Omnibenevolent God would create evil people so that they can be punished for their evil.
So next time you see evil, remember that you deserved it. We all deserved it because we are evil.
You may say: "God created me this way. His fault.".
God created you evil so that he may punish you. It is what a good God would do. How is he going to punish you for your evil if he doesnt create you evil?
When given these two options:
1. Dont create evil and therefore, dont punish evil
2. Create evil and punish evil
We see that in option 1, evil doesnt get punished. Good by definition includes punishing evil. Therefore, creating evil to punish it is the way to go to be all good.