Synthetic Ammonia is a good thing, I agree on that wholeheartedly, however, what Haber did to his family and others to try and appease the Nazis was still pretty bad.
My recollection is that the bad things he did to his family didn't occur during the Nazi period. They occurred during the Kaiser and World War I. His wife killed herself out of protest to his development of gases for warfare. Again, I think this was during world war I.