Comment by hax0ron3

In-universe there was a brutal nuclear war that killed a large number of people. And then after the war they developed technology that got rid of a lot of material scarcity and disease.

I find it somewhat plausible that this could actually lead to something like the show depicts. There is precedent for sweeping moral changes in human history. For example, large parts of the world now find practices like torture, slavery, and collective punishment to be repugnant. Those practices still happen to some extent, but they're not viewed as being just normal like they generally were seen back in the day.

Another example is how Europe and Japan after WW2 genuinely became more pacifistic. Not just as a pretense to fool outsiders, but as a genuine change in how the inhabitants see things.