With WW2, people had a clear goal to look forward to. Ending the war. Today, people are drifting aimlessly and just go through life which causes more dissatisfaction than being in the middle of a war.
For people in occupied countries (Europe and elsewhere), the goal was to merely survive the war and deal with the fallout (death of relatives, destruction of property). Even with drafts, US was a paradise on earth during 1939-1945 compared to much of the world.