As for culture, the Jews famously denied most of what was happening to them as far as persecution goes towards the beginning of the Holocaust. After it got worse (camps etc.) Emotionally, the Jews were along the same level as dirt. Some even believed the lies that were spread through Hitler's propaganda and when taken to camps gave up. The loud and merry life of the Jewish holidays were taken away completely removing almost all Jewish culture during and a long way after the Holocaust. Loss and seclusion for the survivors brought PTSD and many other mental illnesses. So as far as culture and emotions go, Jews in the Holocaust is probably as bad as it gets.
An idiom is a funny saying/phrase. It does not serve as any criminal law or military action. It doesn't mean a foolish person, but it is just an artistic style used in some texts.
