The Nazis were fascists and the communists hated them. Even today leftists with communist beliefs call their political enemies NAZIs or fascists. Communists and fascists had a lot in common. They both believed in one party rule by one dictator. They both hated capitalism. Communists believed that the State controlled everything. There was no personal ownership. Fascists let you own property, but if you didn’t use the property for what they wanted you to, they could take it away. Fascists and commies preached individual rights, but in truth, the only rights you had, were the ones the totalitarian state allowed you to have. Fascists and communists used violence to bring about change. Leftists today are commies and fascists combined, and hatred of Jewish people rounds out their projection.
Actually, Antifa are pretty much just communists or today's version of bomb-tossing anarchists - Fascists were nationalists, Antifa types are anti-national (at least when it comes to the nationalism of Europeans, they're all for the nationalism of Third World people).
Furthermore, Fascist and Nazi anti-capitalist rhetoric was mostly just propaganda to win over working-class voters who otherwise would have supported socialists or communists, in practice neither Hitler nor Mussolini interfered very much with private business or seized private property (except from political enemies in Mussolini's case or from both political enemies, Jews, and other non-Germans in Hitler's case - and then that private property was usually sold off to Italian or German businesses rather than nationalized).
Also, Communist and Anarchist political violence pre-dated Fascists and Nazis by many decades. The Fascists and Nazis simply mimicked the political violence of their Marxist opponents with the logic of "fighting fire with fire", using the same tactics to achieve different aims.