In addition to /u/llordlloyd's comment--which I think goes in the right direction towards questioning the presumption of A: whether the treaty did, in fact, punish Germany, and B: whether Germany did or did not "start the war" (the general consensus among historians is that Germany did, in fact, start "the war" even if it wasn't the first to start the hostilities that would eventually become "the war", World War I).--

I would just like to add: compared to what? If you're assuming that Austria-Hungary started the war, Austria-Hungary was destroyed as a political entity entirely by the treaties of Trianon and Saint-Germain-en-Laye. Even the core Turkish territories of the Ottoman Empire were so completely carved up that the Turks ended up rejecting the Treaty of Sevres and continuing on the fight for several years in the Turkish War(s) of Independence, leading to the creation of the Republic of Turkey, but permanently ending Turkey's 400 year rule over the Arab Middle East.

So when you say punishment and look to Germany's other allies, well, it could have been worse. Germany could have been given what its allies received and destroyed entirely.

The assumption in the question that Versailles either punished, or 'focussed on punishing' Germany is a matter of historical debate. Certainly Versailles was much less odious than Brest-Litovsk, for example.

The problem was the peace Germany could expect in 1918 was always going to be more punitive than one reached in earlier years, when neither side could accept terms upon which negotiations could even begin.

Only a very generous peace treaty could have placated the German right wing and militarists such as Ludendorff, who chose to rewrite history in the 20s and 30s to cast themselves as duped victims. They sought such a peace by appealling directly to Woodrow Wilson for a peace based on his '14 Points', but the other Allies were never going to accept these as a basis and the German leadership would have been aware of this.

The French and British had suffered too greatly, and the public mobilisation associated with total war could never have allowed a benevolent result, either. France and Britain, as well as their dead and maimed, their grieving, had run up massive war debts (notably to US lenders) and France had lost a vast swathe of productive land, and faced massive costs of rebuilding.

The casting of Germany's actions in July as merely 'supporting an ally' has been rather heavily discredited. Germany's general warmaking activities and her willingness to allow war to happen, and her declaration of war on Russia despite Russian diplomats emphasising that their mobilisation did not constitute war, gives plenty of evidence that Germany bore more responsibility for the war's outbreak than any other nation. Several generations of German scholars lead this school of thought.

As it played out Germany had her Versailles obligations under control by the late 1920s, and had it not been for the Wall Street crash and her exposure to irresponsible, unregulated US speculation history could have played out differently with the idea of German victimhood a forgotten curiosity.