One phrase in the video speaks more truth than they intended: "...just a body in the car." It doesn't matter that you hurt and need support, it doesn't matter that going against your natural parental instincts has torn you apart inside. The only thing that matters is to "Do what we tell you to do, no matter what!"
The shunning policy punishes the parents and siblings just as much as the DF'ed, if more. All that matters to Brooklyn is showing that they are the master, and the slaves prove their loyalty through unconditional obedience.