It's no different than the Wizard of Oz's man behind the curtain. By effectively separating himself from this artificial supreme entity, he is allowed to rule with impunity and without question. Man can question man, but man cannot question the supreme. Take the place of the supreme, and viola!
The case of the GB is interesting for sure. They do not directly claim to be God, yet they claim to be God's sole channel. Furthermore, they use standard proof texts to claim their authority, and effectively claim that since God has named them FDS, they are to be followed. They further separate themselves as 'God', by the clever use of third person. When the curtain falls, we realize who 'God' is.
Thanks for this, SD. You always have something great to say.