Why is there even a need to rationalize this? Why do we need to contextualize whether the powerless we're oppressing is "bad" or good"? Those are just merely concepts we develop at our own convenience to justify ourselves for our actions; concepts that we freely alter as and when we need to give a positive justification. You're already killing someone. Doesn't matter what/who/how/where/why.
I'm really disappointed in humanity. We can overwhelm weaker enemy soldiers without guilt but killing a kitten or a child breaks our psyche.
How are we supposed to evolve if this keeps up?
You're demonstrating distinct signs of sociopathy. Nearly any human being who causes harm or death to another human being must rationalize it in their own eyes, at the very least. The what/who/how/where/why is, in most cases, EVERYTHING that matters when understanding human violence against each other. Humans are social animals which evolved to co-exist in communities. We rely on communities to survive. It takes something drastic to break that community instinct and to convince one human that it's justifiable to hurt/kill other members of that community -- anyone in any modern military will tell you that the most difficult thing about training raw recruits is instilling the so-called "killer instinct" into the troops
It's disturbing that you seem to be "disappointed" that most people would hesitate to kill someone who is unable to defend themselves and who is, in the vast majority of societies, undeserving of violent death.
It's also disturbing that you think that devolving into bloodthirsty, soulless murders who have no qualms about taking life is "evolution".
I think you might have that the other way around. To me, it read like white was upset that humans justify any killing, because no murder should be more or less justifiable than another.