Why forgive the nazi germans?

The same reason we forgave Japan: to make them in our own image. Imagine two totalitarian and evil regimes being turned into two of the most prosperous democracies in the world. We did punish the Nazis at the top in the Nuremburg war crime trials. The same is true in Japan, except on a much larger scale. We executed hundreds of Japanese for war crimes. And then Douglas MacArthur reduced the Emporer of Japan to a token figure. He then rebuilt Japan into one of our greatest allies.