So i've had this headcanon for a while, about that siths actually have a whole subculture that isn't told/shown, and we only see the bad side since thats the side that makes the most noise, and the other side is about studying the force in all the mystical ways, and it has dancing rituals,herbology, mithology, etc and its also the side that guards the origins of the jedi and sith.
But because of all the horrible things siths like sidious,vader,maul,etc have done, the nice side imagine is damaged forever and will be judged like if they where the siths that harmed when it isn't like that