Yeah, like I said about the mention of people in Nazi uniforms or KKK robes: these are people who see the world in an extremely black and white way. Those evil white racists are evil personified, inhuman as much as demons are, who can be killed without hesitation or remorse. Unlike orcs, who are people and shouldn’t be portrayed negatively in role playing games.
If an RPG is to touch on real world morality in any meaningful way, it should be as a reminder that morality is complex and nuanced. Of course, if you find yourself in a war, you’re not an evil person for shooting the enemy in front of you, but one of the greatest horrors of war is that all too often the typical fighter is a teenage boy who just thinks he is protecting his people and he’s forced to kill another teenage boy doing the same.
We might have a battlefield situation with a Nazi soldier on one side and a Soviet soldier on another, both are just 16 years old, both serving regimes that killed and oppressed millions, both basically good kids who really want to do what is right, serve their respective countries, and save the world from communism/fascism/capitalism. One will kill the other and it’s tragically a part of every war.
If we’re not just mowing down mooks to relieve stress, if role playing violence is to have real world significance, then it should remind us that our enemies aren’t monsters and that we aren’t saints. That, however isn’t how these sorts of people want to see morality, because they know that the villains of their narrative are monsters that should be destroyed by any means necessary.
I think the point is that those kind of decisions are largely setting concerns, not game system design. Which I'm sure you know, just clarifying for discussion. The
possibility of having an "evil race" is not absolutely necessary but is so useful that for many games for the system to expressly excluded it is limiting the kind of setting and audience it will appeal to. And of course, there are various degrees of 'evil race", too: Demonic, no exceptions; "Members so biologically twisted that the chances of not being evil are too remote to worry about" (in a game design); "A culture marker for this is the way they are absent some good reason why not"; and so on from there.
In my campaign settings, I vary this quite a bit. It's always part of the discussion with the players. Sometimes they want more nuance. Sometimes they want something they can just kill as
part of a heroic adventure (while rescuing others, saving the day, etc.). I make it a point to not just slide the dial universally one way or the other, too.
As an example, in my last few campaigns, "kobolds" have been more neutral and true to their fuzzy mythological roots as I see them. (Whether I've gotten that right or not is almost beside the point.) They are an isolated people with strange habits and sometimes shunned, but not inherently hostile to civilized people. Whereas to compensate, I've made goblins worse than normal, still using tools but almost feral in their attitudes. They are the scorpions in the scorpion/frog fable, where stabbing you in the back is inherent in their very nature--even when it goes against their own interests. The players start with only needing to know, "In this campaign, kobolds are isolated and sometimes shunned but people say you can deal. Goblins want to torture, kill, and probably eat you." The nuance comes later.
I've done this long enough now with the same players that sometimes I can even build on it to put in some misinformation in the basics. Though it is not bait and switch. As in, "As players, you may learn otherwise later, but here is what your characters think they know about other races." Then I'm careful not to change too much or do a complete reversal. The players know when I do that, most of what is in the information is mostly correct, and part of the fun of the campaign is learning the bits that aren't.
"No evil races" in the game design isn't nuance or sophistication or complexity. It's dumb design to avoid facing setting issues. It's also from the same people that in other contexts will say that "everything is shades of gray"--forgetting that "gray" implies the existence of black and white. As soon as we talk about "gray", then that prompts the question, "Well, OK then, which parts are the white and which parts are black?" Nuance is taking the different parts so that the GM understands exactly what shade of gray is present in this creature or culture or race in this setting at this moment.