My dear friend.Its true that at the rule of authoritarian regimes many people die.But then again, people also die in times of democracy.For example the slaughter of the Palestinians by the Israelites as a small example.If you are specifically referring to dictators like Hitler and Stalin then i agree, the difference is great.They killed A LOT of people.Completely innocent people that didn't threat their state.But in other cases(Ioannis Metaxas,Antonio Salazar) they only persecuted people that wanted to destroy their regime,communists in particular and as history has shown as communism killed a hell lot of people than any other dictatorship and while the other regimes did a lot of positive things for their country and their people(stabilized economy,gave more job opportunity) in communist Russia half of the population starved to death.Many dictators are regarded as national heroes.You want to demonize all dictators but history has shown as that in times of turmoil we need great leaders that can quickly reform society.Something that can't happen in times of democracy.