Or they lost the war because of bad execution. They had feifdom fights in the upper ranks and Hitler wasn't able to have anyone tell him he had bad ideas (e.g. war on two fronts and locking tanks in Paris instead of letting them be commanded as needed during d-day (which again came down to infighting)).

Germany was also being worn thin on supplies. It's not as if they were in perfect shape minus allied bombings.

Also, the Nazi ideals weren't terrible in the way a business idea was terrible. Many people bought into it.