Its not about justification. Its about definition. Was Osama a terrorist or a freedom fighter or something else?
Except defining something as something doesn't make it that.
Defining god as good, is no more a explanation for anything nor proving that he is. We still use value judgements, Jesus and the thing he did were good and helped the world, and he's god, I worship him because he's good by his actions.
I have problems with trying to define god as good, or as WLC I think it is uses, "God has to be good, or he wouldn't be worth worshipping." while I agree with this statement, that doesn't mean that the god WLC is good because he's worshiped, that doesn't logically follow.
Also How can something be good, by being the greatest being, good isn't a property, it's a value assigned to something by a outside force, not something intrinsicly good or bad. It's the actions, and the results of those actions that make something good or bad. When you make hardline statements about something being good or bad you hurt others, becuase it's no longer about humans and god, but rules and regulations.
As I've heard put and I like, "Your losing your humanity for the sake of your soul." and are betting on that your not losing your soul.