That's a little reductive. As most things in history, it's a bit more complicated than that. Ernst Rohm, leader of the SA, represented the socialist side of the Nazi Party. Without him it's very unlikely that Hitler would've rose to power as he wouldn't have had the working class vote. The Night of the Long Knives in 1934 lead to the execution of Rohm and every other leader in the SA that supported the socialist side of the national socialist movement. Then they rounded up known communists and executed them, too. Hitler only claimed to be socialist until he had all the socialists killed.
Stalin on the other hand, did some fucked up shit. But, overall, he defeated the Nazis and lifted millions of Russians out of poverty. It's important to weigh the good deeds with the bad. The only good deed Hitler did was make the trains run on time. Stalin did like 70/30 good deeds to bad deeds. We have plenty of US presidents that can't stack up to those numbers.
Holodomor was caused by the Kulaks burning all the grain and slaughtering all the livestock because collectivization threatened their profits. Stalin didn't burn all the grain and slaughter all the cattle, the Kulaks did.