Jehovah's Witnesses who leave the organization are labeled 'apostates'. Many are angry about wasting their life obeying religious leaders who claim to be God's only channel of communication to the entire world!  Now that they have left their religion, family members and friends are not allowed to associate with them or even say a greeting. 
The Watchtower says it's 'God's command' to shun and have absolutely nothing to do with family members and friends who disagree with Watchtower rules. 
'Disfellowshipped' or excommunicated 'apostate' JW's are not treated with the same respect as non-believers. Apostates are looked down upon as wicked, evil persons, unrepentant sinners guilty of 'gross sins' who are 'God's enemies', - even if their only reason for leaving is to join another religion! 
The Watchtower's excuse for hating apostates  is that they 'knew the truth' and left 'God's organization'. JW's believe that apostates have left Jehovah God and went back to a world dominated by Satan the Devil. 
The Watchtower says they are expelling those who are 'wicked' as Paul commanded in 1 Cor 5:13, but critics disagree. The vast majority are not 'wicked'. They merely disagree with the some rules of the Watchtower such as not celebrating holidays, birthdays, Mother's Day, having a blood transfusion, attending another church, practicing yoga, wearing tight pants, etc. ...  The secret Elder's manual 'Shepherd the Flock of God' 2010, gives most of the reasons for disfellowshipping. JW men, women, and children are not allowed to read these rules. Only Elders have access to this important information that affects all JW's. 
Certainly, critics say that both the organization and some Jehovah's Witnesses who leave are not following the instructions of Jesus to 'love your enemies'. Luke 6:35; Jesus told us not to judge because God is kind to the 'ungrateful and wicked'. Therefore the Watchtower's judicial committees and disfellowshipping is a rejection of Christ. Luke 6:27-41
Contrary to what Jehovah's Witnesses are taught to believe, not everyone who leaves and exposes abuse of religious authority is bitter with an axe to grind. Many have found Jesus and follow his word about loving their neighbors even if such persons are hard to deal with.
The way to help people who leave the organization and our dear misguided brothers at the Watchtower Society is to show them a new perspective
based on the love Jesus taught. Jesus is the only path to eternal life.
'Sometimes I want to ask God why he allows any religion to assume his authority and cause so much emotional pain and suffering when he could do something about it. But then I'm afraid he might ask me the same question.' Anonymous
1. Watchtower Shunning Policy
2. The Watchtower Society does not support freedom of religion for members who leave. JW's are told to have absolutely no contact with 'apostates' to pressure them into returning to the organization. See Persecution of Jehovah's Witnesses who leave the Watchtower Society.
3. Secret Watchtower publication gives the real reason why Jehovah's Witnesses are disfellowshipped and that many of the reasons are not 'Bible based' at all. See Shepherd the Flock of God
4. The Governing Body of Jehovah's Witnesses claims to be God's faithful and discreet slave and only channel of communication to the world. The Memorial Celebration of Jehovah's Witnesses shows that millions of JW's don't believe they can't have a relationship with Jesus because God only talks with the 8-12 men who run the Watchtower Society.
5. Jehovah's Witnesses are given only Two Choices - Chose 'God's organization' the Watchtower Society OR the devil - everyone else.
6. 141 Things Jehovah's Witnesses Can't Do (There are now more than 141 rules including the 'you can't be a worshiper of the true God and wear tight pants' rule.)