I'll just give my two cents
I would actually love to see some form of prejudice ingame. Imagine two dwarf civilizations feuding because one civ likes to wear pig tail socks while the other likes jute socks or something. I'm confused as it why it makes people uncomfortable. You can already do some pretty horrible things in dwarf fortress. I just can't see how one evil act or interaction is okay but another isn't. Being able to Genocide entire races is okay but adding in actual reasoning for that genocide isn't okay? (very horrible reasoning mind you)
There are two argument i heard on similar subjects:
1.Peopole try to get away from things in their life with staff like this game, and a guy killing intire villeges on is on isn't happening so they aren't botherd by that (not toovalid inthis example beacuse this is a simulation and all)
2.We have in our culture ש variety of heroes who are heroes for their murder and by such decreased murder implication as bad in stories.
Likely because logic and reason related to prejudice is the absolute worst thing possible to those who tend to be offended by non-politically-correct thinking and statements anyways. The conventional wisdom these days (mostly, I imagine for the comfort of those who would otherwise be uncomfortable) is that anyone who exercises any form of prejudice is stupid, an idiot, ill-informed, etc etc etc. When such a person begins to actually support his or her patterns of thinking with logic or actual facts, those who think otherwise have a tendency to go ABSOLUTELY BANANAS.
It is FAR more threatening when a challenge to a person's closely-held beliefs is backed up by logic than when it is nothing more than ad-hominem type stuff.
Adding prejudice to dwarf fortress won't make it look any more reasonable and might even show how arbitrary it is.
I think that talking on this in detail withuot having some idea on how politics will look in the game won't achive much