One obvious reason (emotional blackmailers punish their victims) is the difference between what blackmailers tell themselves about what they're doing and why they're doing it...and the actual effect of their behavior on us. Punishers don't see themselves as punishing, but rather as maintaining order or keeping a firm hand on things or doing "what's right" or letting us know they can't be pushed around. They see themselves as strong and in charge. If their behavior hurts us, so be it. The end justifies the means.
-- Susan Forward with Donna Frazier, Emotional Blackmail, p. 93