Scribe
Legend
I think it's a bad example for this because it's been actively evolving as a setting for a while, and that's not what people are talking about here.
I read a lot of the fiction, and I think this is maybe overstating the case for any kind of progress in the setting. That said, its an argument for elsewhere for sure.
The point I was failing to make, is that different settings, are able to (and frankly should) have different takes on morality. If we as real humans cannot agree on morality, why can't Dragonlance have a take, and "D&D" have a take, and Dark Sun have a take and Ravenloft have a take?
I get it though, thats a tall ask from Wizards at this point, but...one can dream.