Well, he did try to enroll in the Vienna Art college - only they wouldn’t accept him. Not enough talent to pass the entrance exam.
Still, that doesn’t really explain all that hate for modern art.
Besides, ‘Entartete Kunst’ was organized by the ‘Ministerium für Volksaufklärung und Propaganda’, in other words Joseph Goebbels. He also was head of the ‘Reichskulturkammer’.
If you know what ‘Aufklärung’ and ‘Kultur’ are supposed to mean this comes across as a very sick joke.