Not every gas station, convenience store and pharmacy is stocked with aisle after aisle of cocaine. I don't know I would call it 'evil' but I agree it is a system most people are forced to exist in.
If we're appealing to authority, my mother, my father, and my sister are all highly accomplished doctors, and they believe GLP-1s will become part of a standard drug package to older adults like Statins because it's far more achievable than education we don't have and wouldn't work in the food system that exists in the US.
We're more diligent about ticket descriptions these days, but we weren't always. Obviously the best is to be able to to talk to people, followed by documentation, either explicit documentation or on the ticket itself .
After that it can be useful to look at all commits that were related to the change itself. You can often piece together why something was done from looking at how the changes happened as whole, or even which parts were rewritten as requirements changed.
Another option is to talk to people in your org closer to clients. Support or client managers can sometimes have a better idea of how features are actually used, meant to be used, or what parts are more valuable than product or engineering will, especially if they're revisiting a feature for the first time in many years.
But yeah, often you can't. You're best bet then is to make sure you really understand the feature look at it with fresh eyes. Say "Well this is how it DOES behave, how do we want it to behave from here?" Actually talking to clients can be helpful here if any of them are willing to talk to you. In enterprise software, you can probably find a client who wants to shape the direction of the feature and has some strong thoughts.
You can absolutely disincentivize unethical behavior through legislation though, whether they believe it at the core of their being or not. See slavery, murder, rape, robbery, etc. There will always be loopholes people can exploit, but that doesn't mean legislating away the larger ones doesn't have an effect.
Legislation on education curriculums can also have an impact on people's core morals, though that can be tough when even concepts like "share your toys" and "slavery was wrong" can be called indoctrination these days.
A little tangential since this is more about gating white supremacist content than violence or sex, but I was on 4chan when it was being infiltrated by genuine white supremacist organizations and Russians that talked about how manly Assad was to influence teenagers interested in anime. I had people in real life to talk to about these things so I narrowly escaped the influence. Looking at the current state of the US, not everyone did. That being said, despite my hope that older people would be less prone to such influence, it doesn't always seem to be the case.
If we're appealing to authority, my mother, my father, and my sister are all highly accomplished doctors, and they believe GLP-1s will become part of a standard drug package to older adults like Statins because it's far more achievable than education we don't have and wouldn't work in the food system that exists in the US.