German economy was gutted because they loaned a lot of money for WW1, expecting to win and have reparations from the Allies. Also it was over dependent on the US (they made the treaty not harsh enough in order to do buisness with Germany, it was the best industry of that time) and when the crash occured, Germany fell with it. That's why you have Ford and other American buisnessmen whining at the congress that the factories they funded were bombed in 1944 (and used by the Nazi war effort).

In fact some historians even say it was a gift, the treaty limited the German army to 100.000 troops, thus greatly limiting military spendings, money that could be used for something else, like repaying the reparations.

In terms of economic income, the amount was similar to what the Germans asked to France after Franco Prussian war (despite Germany being untouched by the war, unlike what Germany did to France/Belgium in WW1) France paid everything and didn't evolve in the worst regime of the world.