In addition to Jerry Walls, I recently responded to another commenter on his blog. To quote myself:
Although the Holocaust is a cliché, it's a convenient example of a paradigm-evil. But I could easily use a different example. Take a refugee camp for Cambodians. What if Jerry tells that God would not be good unless he loves the Khmer Rouge?
My point is not that this necessarily disproves the universality of God's love. My point, rather, is that Jerry's facile appeal to "fundamental moral intuitions" is context-dependent and person-variable. What seems to be morally intuitive often turns on the particular example we use to illustrate the claim. Change the audience, change the illustration, you may get a radically different reaction.
Jerry himself presumes to speak on behalf of others when he appeals to moral intuition. He acts as though everyone naturally shares his intuition, and it's only prior commitment to Calvinism (why not Thomism?) that forces some people to deny what in their hear of hearts they know to be true. But that's trivially easy to counterexample.
"Let Jerry explain to Orthodox Jews that he believes God did not want the Nazis to do what they did because He loves all people and does not want the Nazis to do evil or their victims to suffer evil."
And let Jerry explain to Orthodox Jews why the Arminian God did so much less than Dietrich Bonhoeffer to stop the Nazis.
"Let Steve Hays then explain to them that God willed that the Nazis should be evil and go to hell, and that they should do to Jews the evil things that they did, and that God also willed those Jews who did not believe in Jesus to go to hell after enduring hell on earth from the Nazis."
i) There are no nice theodicies. The problem of evil isn't, in the first instance, with any particular theodicy of evil, but with the fact of evil.
ii) It's not willing evil for its own sake, as an end in itself. Rather, willing evil to achieve certain second-order goods. Goods unobtainable apart from evil. In a fallen world, just about everyone exists as a direct or indirect result of evil. Remove the evil and you remove everyone whose existence is the side-effect or end-result of some evil or evils in the past. In a sinless world, other people would take their place. So there are tradeoffs.
iii) Your final objection is not to Calvinism in particular, but Christian exclusivism in general.
iv) There's an asymmetry between my position and Jerry's. Unlike Jerry's glib, selective appeal to "fundamental moral intuitions," I haven't predicated my own position on allegedly universal moral intuitions. Therefore, the fact that Jewish listeners might take umbrage at my theological alternative doesn't turn the tables on my own position.
v) We walk a tightrope when we present a theodicy. On the one hand, some theologians like Cornelius Berkouwer and David Bentley Hart find the very notion of a theodicy blasphemous. For them, any justification for the existence of evil makes evil justifiable. There's no evil, however horrendous, that can't be excused. It can't be as bad as it seems. They think that sanctifies evil.
Mind you, the implication of their position renders the occurrence of evil inherently inexcusable. God had no justification for what happened. But the logic of that position is to either deny God's existence or God's goodness. So that's clearly unacceptable from a Christian standpoint. It's a question of locating ourselves on the right side of the knife edge when we formulate a theodicy.
vi) Keep in mind that, in some measure, the complaint cuts both ways. Maimonides thought Christians were heretics and idolaters (due to their belief in the Trinity, divine Incarnation, and deity of Christ). Those are damnable sins. Just as you have Christian exclusivism, you can have Jewish exclusivism.
vi) Although it may offend some listeners to say that everything happens for a reason, the alternative is to say that some things, especially the very worst things, happen for no good reason whatsoever.
Yet that makes the suffering and death of victims meaningless. But if they think about it, how is that any consolation to the survivors?
People are often conflicted about evil. It may seem pointless, yet they want to know why it happened. Well, it can't be both. Either it has some ultimate purpose or not.