I think in general its a novelty thing, in most games you play the hero so playing the villain is appealing. In practice it doesn't work out so well because when a lot of people get involved in a narrative it becomes difficult to treat the people in there poorly. I think people are hyping themselves that BG3 may be different but in EA we really haven't seen anything other than "save the puppy for a reward" or "Stomp on the puppy for no reason".
