Most of them don't act like adults. They mind other people's business, gossip all the time.
The more you stay away from them because you've figured their nosiness, the more they talk about you behind your back because they are so desparete to want to know about your private life.
They won't leave you alone.
They feel that they are entitled to know everything about you.
They would even go up to your boss secretly and ask them about you because that's how badly they want to know your personal information.
So you would feel uncomfortable working there if you are a sensible and respectful person whose focus is on yourself, not others.