>They didn't.

This isn't up for debate, factually the Weimar Republic failed.

>They did. Germany received about 35 billion marks in loans, almost all of it from the US.

I'm not sure if "here, you owe us even more later", counts as subsidies so much as life support. The problem was the original debt owed because of WWI, more loans would have kicked the can down the road but wouldn't have taken the struggling Weimar Republic into stability.

Recovery takes decades in the best of circumstances, original debts could have effects on the economy for decades. The Treaty of Versailles should have given everyone a clean slate and established a status quo in addition to demilitarizing all of Europe simultaneously. I realize that was unfeasible with France and Britain's colonial empires which required strong navies and armies and the threat of the Soviet Union, but that's even more of a reason to develop a common defense agreement rather than selecting "winners and losers" and then making the losers pay. We know the Treaty of Versailles was a failure, and arguing against that is arguing against history. A stronger Versailles treaty would only have accelerated Germany's road to extremism not tampered it.