It's not just economics there. Weimar was a garbage fire from top to bottom, and that made extremist groups that promised to fix the nation actually viable. People are much more willing to vote for loons if everything is broken and no one has really done much of substance about it. In their eyes they have nothing to lose. A common thought then was "Maybe these nazi/communist/anarchist guys can fix things. They seem well organised even if they are a bit wacky. How could they make things worse? We'll just vote them out if they don't deliver the goods like we did the last guys".
Little did they know of what was to come.