Religion is a sensitive topic and people can become easily upset. That's why almost everyone avoids talking about it with friends and relatives they love. However their relationships don't end just because people in their family go to different churches, - they just don't talk about religion. This is normal behavior. However when people are disfellowshipped, shunned, and called apostates, they try to get their loved ones back by any means they can.
The best thing a Christian religion can do is let people go to an another church they like better. Set them free! But don't take their families and friends away from them. Forcing people to believe in something they don't believe in doesn't work. Let people believe in whatever they believe in and reject everything else.
When people are free, there's no need for them to question the authority of the church. They can attend Kingdom Hall meetings and respectfully listen, - or they can go to another church, - or they can come and go as they like. With this type of system, there's no need for individuals to cause trouble in the congregation. If they don't like one church they can go somewhere else. They are free.
As long as Witnesses know their relationships with God, family, and friends are not threatened, there's no need for them to cause trouble and spread rumors. Because no one wants to anger their friends and family, they will automatically avoid talking about spiritual issues. The primary reason why Witnesses try to turn their family and friends away from the organization's teachings is because all their close relationships are threatened.
If their relationships were not threatened, there wouldn't be any need to convince everyone that they're right and their church teachings is wrong. It's not easy speaking out and causing trouble. People won't do it unless they're pushed into a corner and need to fight to keep the people they care about.