For starters, we should run through the treaties in question:

• Austria: Treaty of St. Germain (signed Sept 10, 1919, effective July 16, 1920). Austria ceded Galicia, Bohemia and Moravia, Trento, southern Tyrol, and Istria. A plebiscite saw southern Carinthia stay with Austria, and another saw the area of Sopron go to Hungary, while Burgenland was transferred from Hungary to Austria. The Austrian navy was broken up and distributed among the Allies, the Austrian army limited to 30,000. The country was liable for reparations, but none actually ever paid. Major points of contention for the Austrians were that it largely overlooked the principle of self-determination: majority German areas went to Czechoslovakia and Italy, but at the same time Austria was forbidden to unify with Germany.

• Bulgaria: Treaty of Neuilly (signed November 27, 1919). Bulgaria gave up Western Thrace (and an outlet to the Aegean) to Greece, and ceded parts of Macedonia to Yugoslavia. The army was limited to 20,000 and reparations of some £ 100 million were tabulated (although about 75% of this was ultimately written off). Bulgaria also had to give up claims to Southern Dobruja, which it had lost to Romania in 1913 and then reoccupied in 1916 (it would eventually get it back in 1947, the only Axis country to actually gain territory from the Second World War).

• Hungary: Treaty of Trianon (signed June 4, 1920, effective July 31, 1921). The Kingdom of Hungary lost approximately two-thirds of its prewar territory and population to Czechoslovakia, Romania and Yugoslavia. Substantial Hungarian populations were outside of Hungary proper, notably in southern Slovakia and central Transylvania. The army was to be capped at 35,000 and reparations amounts and terms to be decided at a later time.

• Turkey: Treaty of Sevres (August 10, 1920, never implemented). This treaty saw Turkey give up all claims to the Middle East and North Africa, grant part of Eastern Anatolia to an independent Armenia and make the rest an autonomous Kurdish region, and cede substantial portions of the Aegean coast and Eastern Thrace to Greece, while providing for Italian and French spheres of influence in Anatolia. It was replaced by the Treaty of Lausanne on July 24, 1923, negotiated by the new Turkish Republic, which saw international recognition of Turkey's current borders (minus Hatay), no cession of territory to Greece or Armenia (the latter of which was a Soviet Republic now anyway), no autonomous Kurdistan, no spheres of influence in Turkey, and no restrictions on the Turkish armed forces or reparations. About 1.5 million Eastern Orthodox people were relocated to Greece, and about 400,000 Muslims relocated to Turkey under a "Convention Concerning the Exchange of Greek and Turkish Populations" signed in January 1923 at Lausanne. Turkey had also gained territory from Georgia and Armenia under the Treaty of Kars, signed on October 13, 1921 between Turkey and the Bolsheviks.

• Russia: I'm assuming the treaty referred to in the OP is the Treaty of Brest Litovsk, signed March 3, 1918. Under these terms Russia gave up Poland, Finland, the Baltics Ukraine and the Kars Region in the Caucasus either to the Central Powers or to local authorities. The former Russian Empire lost a third of its population, and large amounts of its industry and railways (including most of its coal mines). Furthermore, it was fined reparations by Germany. Economic relations between Germany and Soviet Russia were further clarified by an August 1918 treaty, but by terms of the November 11, 1918 armistice between Germany and the Entente and Associated Powers, Germany had to evacuated territories it occupied in Russia based on the Brest Litovsk treaty, and the Bolsheviks annulled the treaty. The Bolsheviks would ultimately reach treaty agreements with the Baltic states in 1920, Poland in 1922, and Finland and Germany (the Treaty of Rapallo) in 1922. The Bolsheviks likewise established diplomatic relations with Britain in 1921 and France in 1924.

So why do those treaties not get the same sort of attention as Versailles? For a variety of reasons.

With regards to Turkey and Russia, a major reason is that the harsh treaties imposed on those countries were ultimately overturned. Sevres was never implemented, and the Turkish nationalists were able to not only overthrow the Ottoman government but also defeat Greece and Armenia, and get occupying European powers to withdraw. In the case of Russia, while Brest Litovsk was harsh and controversial (it was narrowly approved by Lenin's government and not without strong debate) it was seen as a tactical move that would ultimately be overturned by socialist revolution in Germany (which...sort of happened, but not exactly in the way Lenin and company hoped). The treaty itself rapidly became old news as the Bolsheviks fought with the White movement in the Russian Civil War and fought with a number of newly independent states (most notably Poland). The reality on the ground by 1922 was very much the product of force of arms.

As for Hungary, Trianon was considered exceptionally harsh, and is arguably still a dirty word in Hungary today. St. Germain and Neuilly were also harsh and not without bitterness on Austria's or Bulgaria's part. But what makes them different from Versailles were the relative power of these countries, and their perceived situation at the end of the First World War.

Bulgaria and Austria-Hungary in late October 1918 were by anyone's accounts militarily beaten. The Entente broke through Bulgarian lines at the Battle of Vardar, and the Bulgarian government, facing fleeing and mutinous troops, sued for peace on September 30, 1918. Entente forces then were able to march towards Constantinople (leading to the Armistice at Mudros on October 26), and through Serbia and Montenegro towards Hungary proper. The Italian army simultaneously broke Austro-German lines in northern Italy at the Battle of Vittorio Veneto and advanced deep into Austrian territory before an armistice was reached on all Austrian fronts on November 3. This was paralleled by Romania re-entering the war, and internal collapse of Austria-Hungary: Hungary ended its personal union with Austria, Czechoslovakia declared independence, and the "State of Slovenes, Croats and Serbs" declared its independence all in October.

Germany was militarily beaten, but it didn't quite appear as obvious to Germans as it did to Bulgarians, Austrians, Hungarians. The German military was still outside German borders. The German navy was still in German ports (albeit with its sailors mutinying). From the average German's perspective, the war wasn't a total defeat, but a moment to sue for a negotiated peace. The actual terms of the Versailles Treaty, however, were not negotiated with German input, but rather determined by the victorious powers, who still maintained a naval blockade of Germany until the signature and ratification of the Treaty by German representatives. The war seemed to be "lost" on the home front because of soldiers' and sailors' mutinies leading to the 1918-1919 Revolution, abdication of the Kaiser, and establishment of the Weimar Republic - hence a "stab in the back" myth that was conveniently propagated by senior members of the German military as a helpful obfuscation of the fact that they themselves knew the war was lost at that point. That republic bore the brunt of blame for signing the treaty, which furthermore seemed hypocritical in that rather than promoting self-determination, it actually stripped Germany of territories inhabited by Germans and imposed (in German eyes) a hefty reparations sum. In short, the Treaty seemed unfair to Germany as a great power and was universally opposed by the German political spectrum. It was really more a question of how to change the postwar order that separated German political parties. Where the liberal Gustav Stresemann sought to address the Versailles order through diplomacy and integration of Germany into international institutions in the 1920s, Hitler would try to change the Versailles order through unilateral action and aggression in the 1930s.

So in many ways it was less that the terms of Versailles were harsher than other treaties - in many ways they clearly were not, and even those terms that did pass, such as German reparations, were repeatedly renegotiated before being suspended. But it was the fact that Germany remained a much more powerful state in a way that Austria, Hungary or Bulgaria were not that made its bitterness towards the peace more dangerous to the postwar order. The fact that most Germans saw the peace as forcefully imposed and unfair both in its terms and its perceived hypocrisy meant that there was also never really a serious base of support for abiding by its terms indefinitely.

Greetings! In addition to u/Kochevnik81's excellent duo of main comments regarding the Treaty of Versailles in relation to the other treaties of 1919-1920, I wanted to weigh in on a few key points brought up in those comments. More specifically, the following:

The infamous Article 231 or "War Guilt" clause stated:

From the average German's perspective, the war wasn't a total defeat, but a moment to sue for a negotiated peace. The actual terms of the Versailles Treaty, however, were not negotiated with German input, but rather determined by the victorious powers, who still maintained a naval blockade of Germany until the signature and ratification of the Treaty by German representatives.

It was the Germans who approached the Allies through the American President (Woodrow Wilson) in 1918 to look for options regarding a negotiated peace. There was not, as would later be reported, a critically serious food or supply shortage on the home front which led up to this moment. Granted, the food supplies and armaments resources were at a low, but the Germans had already managed to survive (but just barely) the "Turnip Winter" of 1916-1917 and it was projected that rationing would hold off the "hunger disaster" until about 1919 or 1920. The reasons behind the German leadership looking for the armistice and a negotiated peace were to do with several key factors:

• The Balkan front, as Kochevik81 points out, was in serious trouble, with Bulgaria and the Ottoman Empire rapidly approaching the breaking point of their war efforts. The Austro-Hungarians were also weakening at an alarming rate, and their leader in 1914, Emperor Franz Joseph, had passed away in 1916. He had been succeeded by Charles (or Karl) I, who had failed to remove Austria-Hungary through separate peace talks beforehand. The Italian victory over the Austro-Hungarian army at Vittorio Veneto was further proof that the Central Powers were cracking at the seams.
• The military duo who led the German war effort, Erich Ludendorff and Paul von Hindenburg, were also doubtful of the German Army's abilities to hold off against a combined Anglo-French-American offensive (which did later materialise in the 100 Days Offensive, and as they had gloomily predicted, the German Army did give up considerable land). They feared, Ludendorff in particular, that if the Germans do not seek a peace with the Allies now, there will be a catastrophe on the Home Front if a military defeat is the reason they are forced to the negotiating table. Ludendorff fears that if this is allowed to happen, the German Army (which has seen an increasingly high number of mass-surrenders since August of 1918) will become a militia (or as he termed it, a militzarmee).
• The Germany Army has also gambled away its initiative on the Western Front in the Kaiserschlacht Offensive of Spring 1918 (also known as the Ludendorff Offensive). With the Americans now in the war proper, military High Command estimates that 1919 will see the Allies reach German soil, and that may lead to political chaos (but not widespread revolution) on the Home Front, further complicating peace negotiations.

In light of all these considerations, the Germans do take the initiative in seeking peace terms, though it is to be noted that they went directly to Wilson, and not the Allied generals. As such, it seemed reasonable to the Reichstag (parliament) that the Germans be accorded a spot at the negotiating table. When this was not the case, there was immediate concern that the Allies would (as it actually happened) dictate a peace treaty with conditions and requirements contrary to what the Germans desired. Below is a short recap of how the Germans experienced the Paris Peace Conference, adapted from an earlier response.

The German delegation at Versailles was composed of several key figures, all of whom brought some form of political agenda and feelings towards the Treaty. At it's head was Reich Minister for External Affairs Count Ulrich von Brockdorff-Rantzau, Reich Law Minister Dr. Landsberg, Reich Post Minister Johannes Giesberts, Prussian state president Robert Leinert, financial advisor Carl Melchior, and Professor Walter Schueking. All these men had practically the same reaction to the terms when it was presented to them on May 7th, 1919: utter shock and rejection of the Allied terms. Upon receiving the Treaty from French Prime Minister Georges Clemenceau, Brockdorff-Rantzau famously remarked in his speech:

"It is expected from us that we should accept the guilt of War. This statement would be a lie in my mouth."

The problem with the German's position however, meant that the delegation was incapable of altering the Treaty in any way, shape, or form. By not involving the Germans in the peace negotiations or the treaty writing process, the Allied Powers had essentially stripped all chance of getting the Germans to agree to their terms without the torrent of complaints which inevitably followed. Almost immediately after being presented the Treaty, the German delegation began drafting and sending "notes" to the Allied delegations about the impossibility of fulfilling the Treaty conditions, and some included counter-proposals to specific questions. Here are some of them:

• Protest on Reparations: The war reparations which Germany had to pay were crippling to say the least, and what's even more shocking is that no one quite knew how much Germany had to pay when the Conference was concluded. In the end however, Germany offered
• Clause 231 (War Guilt): On May 13th, 1919 the delegation from Germany protested against the "War Guilt Clause", which stated that Germany accepted the responsibility (and hence the blame) for starting the Great War. The German text of this protest actually reads:

"The German people did not will the war and would not have undertaken a war of aggression. They have always remained convinced that this war was for them a defensive war... They cannot consider the former German Government as the party which was solely or chiefly to blame for the war."

• Clemenceau responded to this protest by bringing up a note from November 1918 sent by the previous German government to US Secretary of State Robert Lansing, in which Germany admitted that she was indebted to make reparations on account of "Germany's aggression by land, sea, and air."
• The Germans did agree to the concession of Alsace-Lorraine back to France, but vehemently protested the Treaty's stipulation of giving up the coal mines in the Saar Basin, the East Prussian corridor to a newly-formed Poland, Eupen-Malmedy, Upper Silesia, Prussian Moresnet, and various other German-run districts in what would form Poland.

These are of course, shortened versions and by no means an exhaustive list of the German protests at the Treaty of Versailles. The general experience of the German delegation was one of constant rejection and at times blatant antagonism by the Allied peacemakers. The chaos caused by the peace terms caused so much upheaval back home and in Versailles that Brockdorff-Rantzau left the Paris Peace Conference, and Germany's first democratically elected Chancellor Philipp Sceidemann resigned on June 20th over the Treaty. The Allies pressed the Germans, essentially giving them an "ultimatum" to sign the Treaty or (at least in the minds of the German government) face a renewed invasion of German territory and a continuation of the armed blockade. The new government quickly dispatched Foreign Minister Hermann Mueller and Colonial Minister Johannes Bell to accept the Allied peace terms, and the Diktat von Versailles (Decree of Versailles) was signed by the Germans on June 28th, 1919.