Nazi science usually was proper science:
Mengele was only one of a number of scientists in Nazi Germany who carried out research on involuntary human subjects. Karl Gebhardt and Fritz Fischer had women prisoners in the Ravensbrück concentration camp injected with harmful microbes. They then tested new drugs on the prisoners, presenting the results to a scientific conference.
Many such projects were directly conceived as practical contributions to the German war effort. In a variety of camps, SS doctors used inmates to test treatments for injuries sustained in battle, cutting open their calves and sewing bits of glass or wood or gauze impregnated with bacteria into the wounds, sometimes even smashing the prisoners’ bones with hammers to create a more realistic effect; again, the results were presented to scientific conferences without anyone offering any criticism of the methods employed.
It’s always interesting to see how science fetishists attempt to dismiss Nazi science as “bad science” without ever explaining what the difference between “bad science” and “good science” is. I also note that for these same people, “bad theology” is seldom seen as an acceptable excuse for even completely unrelated theologies. If it’s reasonable to attack Christians because of the actions of Muslims, then it’s perfectly reasonable to attack scientists because of the actions of their historical German colleagues.