Agreed. I'm not crazy about the idea of DF espousing a cultural hierarchy or associating "uncivilized" practices with evil.
Well...doesn't it already in some ways? Dwarves don't kidnap Goblin and Kobold Children. They don't steal. (Admittedly some dwarves end up doing much worse things.) There is some of those fantasy stereotypes already part of the game, and by all accounts, more will follow. What about the semi-sentient cave dwellers and the weird stuff? This isn't a statement about the game's intent or anything...it's just how it's presented now.
With the armies arc and such, and the level of detail creature and civ descriptions can and will include, different civs dominated by "evil" baddies masquerading as gods...associations between non-dwarf civs and evil are going to happen at some point just because that's how the world spits it out. And eventually, yeah, you're going to culturally dominate them. There's going to be a very large "Age of Exploration" arc in DF at some point.
So scarification. It's ok is ok if it's on your dwarves by player choice, but not ok if it's on goblins and others just by the way the world gen shook out? Not trying to attack you here, just looking for where you believe the line is.
Personally, I'm ok with it as a procedural element. Making it permanently part of other cultures descriptions leads to speculation about motive. Making it part of the procedural process, you can't accuse the computer of racism. And it's not really in the spirit of DF to stereotype. (Much, anyways. The Elves get it pretty rough....) The only things I object to are examples that seem to be there just to plumb how uncomfortable it could be made. We don't need to make circumcision (sexual orientation, some others) ect.. part of civ traits just because it can be done.