There has never been a time when everyone behaved morally, and it's unhelpful to view the past in this way.
MLK himself was murdered.
I have this quote painted on one of my favorite possessions. I live by the quote, I'd die by it. I don't consider that childishly naive.
Naive would be thinking that taking a more Malcom X approach won't lead to death and prison as well.
Such as using less optimal solutions that align more with their beliefs or taking a lower paying job that won't compromise their morals.
Principles are 'wrong' just like scientific models are wrong. Over time, scientific models get replaced by other models that are less wrong.
What I want to say actually : there is no Right or Meaning just like there is no Truth. There's only (wise) man's search for it.