despite fighting a 3 front war there was never an enemy bullet fired on their soil. Germany's surrender was political. Its civilian populace lost its resolve to keep fighting.

That didn't happen in WW2. The Germans had a greater resolve and the Allies essentially had to wipe out their military. So why was it different? I think there are a few reasons but the largest is that WW2 was a total war. I think a lot of people didn't like that Hitler took them into another war but when the Allies started dropping bombs on their cities and blowing up Granny it seemed to harden their resolve.