do you think the amaleikim wont and shouldnt dislike us when you kill their children? let them hate us. we wont care. Hashem said to. your argument has no shaychis.
It has no shaychus for those who sincerely believe that Hashem is in charge, and had the Holocaust not happened, the 6 million would have died in another way. No Shaychus for those who believe that Hitler was a tool of the Ribbono Shel Olam, just like Paraoh (who granted, there is a discussion why Paraoh is blamed for something that Hashem decreed, but that is a different issue).
However, for the “never again” crowd, for those who blame the Hamases & Nazis of the world as if they have their own power and they are not a tool of Hashem, for them the arguement is strong. Because logically they are correct, based on their own reasoning. And on that point, you cannot blame them.