I have only quickscanned / not really read the article you refer to, but as for speaking up against Nazis ... well, it DID take a lot more courage than today because there essentially was a tyranny in place. And I think a lot of people stayed silent simply out of fear for their families.
You certainly have heard about Die Weiße Rose, yes? Brave young people, those. https://en.wikipedia.org/wiki/White_Rose