So Sylvanas killing to send souls to the maw to make herself and the jailer stronger so they can in act their schemes isn’t a reason. But Garrosh rationalizing reasons in his mind that he knows isn’t true but use them in a hypocrite way to make himself feel better is a reason to kill?
Garrosh was killing people to soothe his feelings, windrunner was doing it to strengthen herself. Both horrible evil acts, only one of them was doing it for no tangible reason other then to kill.