In All Quiet on the Western Front, how does Mittelstaedt taunt and humiliate Kantorek and is it justified?

In Chapter 7 of All Quiet on the Western Front, Paul's classmate Mittelstaedt torments their former schoolmaster Kantorek.  Kantorek has enlisted as one of the reserve soldiers, and he proves that he is a poor soldier when it comes to combat.  However, Kantorek truly believes in the war effort, and he is the one who has persuaded Paul and his friends to join the army upon graduation; Kantorek continues to encourage boys to enlist as soldiers.  After Paul and his friends fight on the front line, they realize that Kantorek's persuasion is all talk and that Kantorek has no idea what it is really like to be a soldier.  Mittelstaedt sees Kantorek in town and forces him to dress like a clown and parade around humiliated.  One could argue that Mittelstaedt's behavior is childish, crude, and inappropriate; however, from Mittelstaedt's point of view, Kantorek is responsible for sending the boys into unknown horrors on the front line.  The boys think that Kantorek is a fool, so Mittelstaedt makes him dress like one to symbolically represent the misguided notions that drive Kantorek's (and others') patriotism.