Bedrockgames
I post in the voice of Christopher Walken
I generally agree with you. I also think that most people in this debate seem to consider humans to be 100% free-willed, with no instinctive drive at all, or they take human insctinct as a baseline for any sentient species that one could meet in D&D. So "a drive to do X", where X is a behaviour that would be labelled evil, is dismissed as a lack of free will, despite our own drives (sexual drives, overeating drives, fear...) governing our behaviour more often than we'd like.
And one issue you run into if creatures don't have will, but are tethered to good or evil by design, is their isn't any real moral choice being made, so you can question whether they are truly good or truly evil. You can get around this by having it be the product of a choice made at a very early point in history, like angels and demons making their choice shortly after the moment of creation, but that only works for eternal beings, not for mortal ones.
But I think D&D alignment and moral cosmology is more epic in nature. I usually go to other games when I want more involved, real world or interesting morality (and I only play D&D once in a while these days)