Everyone is saying that it's because we're social animals. This is not just a saying, and we can't overstate the importance of that. When talking about a topic like this, or morality, I usually say 'humans are intensely social animals.' Our identity in the group is immensely important to who we are and our overall well-being.
This is not something we can fix by saying "Get over it," or "Snap out of it."
Social isolation can be deadly
So many in the JW community suffer through this, and it's why we say it's far worse than just the WTS being meanies. It's abuse.