Poor folk, indeed! I have no doubt that the holocaust happened, and feel nothing but disgust for the prepetrators. No person deserves to be treated in that way, and the world is well rid of the Nazis. I do think it is good that it is taught, if only to demonstrate the thin veneer between what we think of as a civilised society, and the unfettered unleashing of underlying tensions, hatred, and self interest that are the basic embodiment of what I think of as evil.
But in contrast, here in "civilised" Britain, we used to do worse to our own! We've just been for a day out and visited the original Clink Street prison (the origin of the term "Clink" to mean jail"). Only a few hundred years ago in London, they would torture, main and disfigure people and let them live out their days in pain and misery until they died a horrible forlorn death. Examples included lead collars with spikes in them designed to cut and torment the wearer (and having the side-effect of giving them lead poisoning). How about metal boot that was put on the foot, and dry wood packed in; it would then be filled with water so the wood would expand and crush the foot of the unfortunate wearer, probably making it fall off. Or winching people up by their arms tied behind their back. Or even having arms and legs in stocks, but off the floor. Or maybe ripping people apart by tying each arm/leg to a horse pulling in each direction. Oh, and there were no toilets and the place would often flood up the 3 ft of water from the Thames, meaning everyone was bathing in raw sewerage (also nice for all of the wounds!).
We live in privileged times, but we should not forget the past, and how easy it would be to lapse.