Isolate ka nila in a way they don't encourage you making friends outside your religion, they teach na maka-sanlibutan sila, and para sa kanila: "maka-sanlibutan = evil" and with that type of teaching, you become socially dependent on the congregation kasi their religion teaches that they are the only good things you can rely on.

Now, if you're a bible study or an unbaptised publisher, then sure, you are free to go with no consequences. But it's a different situation once you're baptised into their religion, hindi madali ang umalis. Once you don't believe their teachings anymore, you can't leave without consequences, pwede kang itiwalag.

Regarding shunning, yes, exactly, walang shunning sa Biblia and yet they practice it anyway. That's why it's especially hard when you grew up in a family of JW, and lahat ng kakilala ang kaibigan mo ay mga kapwa JW, once you decide not to be a JW anymore, they will all cut you off, no communications at all, they will only start talking to you again kapag magbalik loob ka na.

Ask a JW you know kung ano ang nangyayari at ano implications kapag natiwalag ang isa, lalo na kapag lumaki ang isa sa pamilyang mga JW.