Based on the premises of Nietzsche (was he driven mad by the consonants?), there is no "just," no "justice," no need to "justify" anything. There only is what is, and the main categories of action are "possible" and "impossible." The Holocaust, events proved, was possible, and nothing further need be said.
Our general use of language, as the author shows, doesn't lend itself to communicating this concept. We instinctively seek justice and justification. The answer to the "atheist's" question about how there can be a God when the world is so dreadful is, "What's dreadful about it? This is the world you want, with no objective standards and no ultimate meaning. The mass murder just 'is,' same as you, and what difference does it make?"
Exactly. Well said, tax-chick.