He also hated the Slavs. They were "subhuman". I believe he changed his point of attack a few times...wanting to go for the oil fields, then switching to Stalingrad for the symbolic victory, and generally not doing what his generals told him to. Also, Russia was producing T-34's one after the other. A very good tank that was easily manufactured. Winter set and fucked the Germans. Then they had to worry about the other front.