I am not sure if it has to do with revenge as much as it may have to do with setting the record straight.
As a JW I was told that Jehovah was 'sweeping house' in the 70s and that apostates had intentionally infiltrated the Watchtower Society in an effort to do great harm. I was also told that those who left were only in God's organization for paradise and not for God himself. When I read CoC it came across as more of a 'setting the matter of truth' straight and the moral delimas involved in the legalistic agenda of the WTS.
When we are in court, we listen to both sides of the story. I find the WTS only offers their version of events and then scare those who dare to investigate the whole story with tactics like 'the devil is out to snare you. or that they are apostates with only one agenda -- to rip you away from Jehovah'
Once you take the leap and dare to investigate the other side of the story and discover that the WTS lied to you and that the 'so-called enemy' was speaking the truth regarding specific matters, its hard to keep quiet. Some of us lick our wounds in the corner while others feel very dedicated to exposing the lies.
The WTS spends a lot of energy diffusing outside sources of truths with scare tactics. So I think its all fair game.