The title itself speaks volumes. In the debate about human personality development Skinner argued that pre-conditioning was everything. Since everything is pre-conditioned all types of blame statements become meaningless. In fact we're forced to give up the idea that evil or good even exists at all. It is merely an imposition of a moral category on something that has no innate moral substance at all.
Nothing is ultimately bad.
Nothing is deplorable. Nothing is tragic or worthy of blame. Nothing is ultimately good, honorable, noble, or worthy of praise. It's all lost in a twilight zone of moral nothingness. Moral language becomes incoherent, which is precisely what this article suggests.