To put it concisely, the OT of the bible says to separate yourself from evil doers, the WTS takes this onto their own, specifically identifying who is evil and who is obedient (righteous), this includes people who poignantly disagree with the WTS doctrines which are many times noticeably false.
They take and exploit these certain scriptures to serve their own means, The WTS. uses this shunning policy to control people's behavior and appearance over to who they want as their openly obvious sales representatives. Essentially making them the master and their allured followers the weaker designated spiritual slave.
This also creates a semblance of power to those leading men, uplifting their perceived power and personal stature toward themselves.