To give an intellectually honest guess, I'd say the honest among them think that form of socialism is the best way to handle resources and that violent revolution is the only way to get there effectively. The dishonest among them likely just wanna exploit the rest of them.
The Nazis called themselves "national-socialists", because socialism was popular at the time. Anyone who actually wanted socialism would have voted for the social-democratic party (SPD) or the communist party (KPD). The actual politics of the NSDAP were very much focused on the nationalist, xenophobic part. You just rarely have the baddies calling themselves "the baddies party".