Sepulchrave II
Legend
I was about to post something similar before I came across your post.I am perpetuity amused that D&D tries it's darnedest to avoid the fact that a group of well armed mercenaries slaughtering sapient beings would be a war crime in the real world. "No no no, they're really fey/elementals/fiends/etc so it's totally different" is just the latest in the long line of justifying to itself the violence at the heart of the game.
I understand the urge to treat humanoids differently (these sophonts resemble us too much, and we shouldn't de-personize them), but in a sense that is itself more inherently problematic (i.e. it's ok to de-personize and kill sophonts that don't resemble us too much).
I don't think you can really get away from the fact that it's not ok to kill sophonts.