“Just” means that punishment is deserved. Well, ??? ???? ????, so every punishment is deserved, and it’s futile to argue that our sense of justice is more correct than Hashem’s.
Hashem is “good” – the entire universe was made so that he can bestow god upon his creations, and the ultimate good is reward which comes through difficulty, through achievement, and at risk of falling and suffering consequences. We may not prefer it, and in fact, Chazal said “??? ?? ???? ??? ????”, but it’s still ultimately for our benefit.
And of course it gives perspective – if not a perspective on any particular individual, on the direction of klal Yisroel, which unquestionably changed.
Again, I haven’t read the book, and I’m not here to defend it or the title, but I don’t think you are correct to completely dismiss the basic argument.