The game teaches you that sometimes what’s good for you isn’t good for the many and vice versa .
Sometimes you have to make hard choises and for me I always chose power over morale.
I let my buddy be the winner and ascend especially given the fact that I myself am the uncrowned prince of House Baal.
So it’s a fitting for a dark urge to have at least some powerful Allies who also chose power over goody two shoes choises and Astarion is perfectly made for this
The child of Baal, the ascended vampire and the daughter of Darkness sounds like an excellent team.
If you only get rewarded for being nice there won’t be any point in ever doing anything good.
Plus in real life it’s the same thing, you have to sometimes screw the others and chose what’s good for you else you are just going to be one of the many