I used to think part of what made the Nazis bad, in addition to their horrible beliefs, were their horrible methods… starting with book burnings, smashing businesses, and progressing to the true horrors: lining up people and shooting them, and of course gas chambers

To me the actions were wrong in and of themselves.

But it seems that a lot of people I know don’t think the actions were wrong in and of themselves but were wrong because of who they targeted

Which opens up a huge can of worms

That's basically the horseshoe theory in a nutshell. I've always been a believer in the horseshoe theory:

The more you believe in something, the more you believe the ends justify the means. And the more you believe that the ends justify the means, the more similar those means tend to become...