Someone hasn't read the Old Testament. God mellowed out when he had a kid, but before that he smote entire cities. Sometimes God did it himself. Sometimes God ordered Israelites to commit genocide.
You're saying that Old Testament has "a strong, well-defined internal logic"? If so maybe you could do some more reading. I don't think e.g. Genesis and Job fit together at all... how about Deuteronomy and Ecclesiastes?