Yes, it was. The Treaty of Versailles made Germany take full responsibility for World War I, even though the war was the fault of multiple countries. It also made Germany pay extensive war debts to pay for the damages of the war, which completely destroyed Germany's economy with inflation. The Treaty of Versailles also severely limited Germany's military, which was very important to them. So Germany's response to the Treaty of Versailles was legitimate due to the severe punishments inflicted on Germany which were very harsh for a war that they did help initiate, but were not completely at fault for.