Well, I was told that the commandant of the Auschwitz camp was a rather cultured person as well. He would play classical music to silence off the screams of people being gassed next door. The VonBrauns and hi-tech wizards that pioneered modern rocketry also created the Dora "Mittelwerke" - a murderous forced labor camp manufacturing V-2 missiles.
The Pinochets and Polpots were probably very sincere individuals too. For that matter, General Sherman reportedly had a very warm attitude toward the Southerners.
In the world of charming tyrants, I have less and less problems with burning intellectuals and leaders at stake for the consequences of their policies - whether intended or not - their personal charm notwithstanding. I could show some sense of humor too, for example asking them if they would like a smoke before the pyre is lit. Human robots coldly inflicting misery on others in the name of abstract principles or ideology are probably the most scary monsters - real or imaginary - that walked on the surface of this planet.