There is a huge difference between doing right because it is the right thing to do, than doing “right” because it is the practical thing to do to aid the survival of the species. In the latter case, “right” could mean eugenics and genocide. The Nazis truly believed they were advancing the species with their human experiments and culling of the weak and infirm, and as such, they considered themselves “good.”
Those shocked at the Nazi’s did not condemn them for simply being in “error that their actions were not helpful for the survival of the species, they condemned them because their actions were wrong and evil in the absolute sense i.e. they were wrong even if their actions DID advance the species.
I respectfully disagree. The Nazis did their best to hide and cover-up their crimes. They committed them under the fog of war. They new what they were doing was wrong, evil and unacceptable and possible only in the most extreme of circumstances. They saw their actions as the "necessary" thing to do, but never considered it "good".
I would challenge you to produce any primary-source historical documentation (the random musings a low-level SS automoton) that shows otherwise.