The current practice of disfellowshipping, shunning, and judging people on behalf of God is based on the fear that a bad apple will spoil 'God's organization' or make it unclean in some way.
Unfortunately these practices have a negative effect on the organization and individual Jehovah's Witnesses. See Mental Illness When Jehovah's Witnesses are unhappy because they are grieving the loss of loved ones who are disfellowshipped, problems arise within the organization.
When people are free to come and go as they like, to listen to God in prayer and meditation, to exercise their own conscience, to have a direct relationship with their mediator Jesus Christ- ... without the threat of being separated from their loved ones, there is peace within the congregation. There is no need for anyone to spread 'rumors' or turn people against their faith.
Ironically in an attempt to keep congregations 'clean', it has exactly the opposite effect. Christians know that it's God's job is to judge the wicked and the righteous. Disfellowshipped Jehovah's Witnesses are 'cut off' from family and friends as if God threw them out of his organization, when in fact he has not. We know this because the Watchtower says it has no divine inspiration.
Also every country also has a police force and judicial system to investigate possible criminal activity. If people are found guilty, the will be automatically sent to jail and expelled from the congregation. There's no need for a church to meddle in God's business.
By forcing people to obey their every doctrine as if it comes from God, some look at it as a modern day form of idolatry. It's best when people have the Christian freedom to worship God according to their conscience and personal understanding of God's word.