Another few things that bothers the shit out of me with Karlachs endings:
1) Her endings are decided by a dialog click in the last 30 seconds of the game
2) Her quests, aside from being shallow, literally don't matter to the ending. Die or go to hell.
3) Locking her out of a good ending locks me out of the endings I want if I don't romance her. I wanted to sacrifice myself as the Mindflayers and save everyone. That was my tragic endings but I can't HAVE that because if I die, Karlach fucking explodes.