When it comes to ExJWs, I believe a large part of it is that the GB have replaced Jehovah, or Christ in many respects.
To JWs, the GB are like Moses, or the Apostles, a visual anchor of the proof of God, and this is achieved through "awe" or celebrity status. It's like fans all faint at Michael Jackson, there is some "other worldliness" to it (and MJ was raised a JW, it seems he picked up the method very well, perhaps subconciously, as he would purposely make himself "Christlike" to gain worship of his fans and the masses through words, visual images, symbolism and characterisation).
Because they supress freedom of infomation, everything they learn comes from the GB, and so they become in a sense like "a father" to JWs, telling them right from wrong, truth from lies. Thus, many JWs do not develop a relationship with Jehovah, or with Christ, they have a relationship with the Organisation and the GB, and Jehovah and Jesus are "proxy" through that "channel".
You don't fully see it as a PIMI. The GB are the ones "responsible" for everything, but when your relationship with Jesus and Jehovah is personal, that there is not "guardian of doctrine" other than 'all' of us as Christians together, united in brotherly equality,and shepards are just shepards, encouragers, not people with "more divine knowlege" than the other brothers, 'then' you truly all the more so want to please them, to do what is right, to know right from wrong, because it's also "on you" directly.
But for the ExJW athiest, the GB was God, they did things because they were forced to by men, and to live up to "social expectations" around them. And because they then realise with proof that the GB's doctrines are wrong... suddenly, GOD is wrong, as since their induction (for many, since birth), the GB's teachings, and God are one in the same. And it's sad. And it is also one of the crimes of the Harlot, "stumbling the little ones".
Another reason is that, many ExJWs are indeed people who wish to be godless, this can't be denied, those kinds are out there, they want the life of immorality. But this in part is encouraged by the Organisation's tight control, and pharisaical rules, which supresses and represses individuals and their normal desires, interests, social needs, and more. So the Bible's laws, the laws of God, become associated with pharisaicalism, and it cuts people off from the love of Jehovah and the freedom we have been bought.
So, what happens is, people want "athiestic freedom", because anything to do with God is imprisoning to them, they don't know anything else, and all the other main churches teach falsehoods and hypocrisy all the same, so who wants that? And so, these ones conclude there is "nowhere" to go. It's these ones who often work hard at debunking the false doctrines of the Org, because they've been trained to do it best by the Org in regards to other religions. And thus, most doors to freedom from Bablyon come from these athiestic ones... what a clever Satanic ploy right? Make people hate God through Satanic means, then introduce Satanism as the only escape.
Many ExJWs also become cold, agressive, judgemental, name calling, spiteful, because 1. they are in pain and trauma from what they have been subject to, and 2. they have not let go of what the Org (and in many cases their overcontroling and judgemental parents) have taught them to be (since when you really pay attention, JW congregation members are on one hand, very loving God devoted individuals, but on the other, very judging, and looking out for "who is a good or bad association" and trained to view sinners with an eye of disgust and alienation), so even when leaving the Org, they remain "cult minded", black and white mentality, but without "God" in the mix all they are left with are the negative elements, from extreme over righteousness to extreme unrighteousness.
In this I have been fortunate. I always was someone who studied for himself as a PIMI, searching for proof of the Bible's inspiration and existence of God, outside of the Organisation's materials. I did it for myself.
As of now, I am a PIMO of the Organisation, and I've never had to suffer any victimisation. My family have never been controlling, I've had a lot of freedom in my life (compared to others raised in the Org), and I've always been very happy where I am. What woke me up was not ill treatment, desire for freedom to sin, nor anything which caused me to be disgusted with the Org. Rather it was reading the Bible indepentently and objectively, and fairly giving both sides (opposers and supporters of the Org) a voice (always, even since I was very young, found it hypocritical that we could convert and disprove us others, but they could not convert or disprove us).
Thus, Im not one of these "damaged ExJWs", I'd better describe myself as an "awoken one" through means of the word of God. And that's why I don't consider myself a JW anymore in heart, but I am a dedicated Christian all the same, and I appreciate the "actual truths" the Org taught me since youth, and I do not consider my door to door work, or my attendence to the meetings all these years as "wasted" because no time dedicated to God is wasted, even if mistaken, it builds character and God appreciates those in service to him from an honest place in the heart.
"The fruitage of the Spirit is; love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, and self-control..." Galatians 5:22-23