The reality isn't black and white like they put it. Not everyone outside is all bad just cause they don't conform to the standards of a JW. I'm a born in and still young, but I never really had any friends in the congregation even while still believing in religion. I did notice while growing up, that there were some younger JWs who would do things they shouldnt have like date, swear, smoke, and hang out with the wrong people. At the Kingdom Hall, they were seen as good young people in the congregation. I never did those things but it got me to question what we were being told. Plus I always had "worldy" friends at school, and even though there were times when it was difficult to relate to them, they still respected my religion and didn't push me to do bad things. They didn't really care if I was a JW and were helpful, good people. What is interesting is that I felt like I could be more like myself, and more relaxed with them and with people at school than at the congregation.
My point being: it's more about finding the right people who are good to be around with. What the Watchtower does is use fear tactics; they demonize and highlight the bad on the other side to scare people, and when the people swallow those ideas, they avoid the others. It creates a separation, a barrier and a way of control.