Why would it be mad? Because Hitler singled out an ethnic group for extermination in addition to political opponents rather than just killing off political oppo

Why would it be mad? Because Hitler singled out an ethnic group for extermination in addition to political opponents rather than just killing off political opponents? They both racked up a comparable body-counts of their own people as rulers (well, enough for both to be consider mass-murders, though I understand that Stalin had a high body-count).