I believe the GB's takeover of the FDS was an illegal coup - not illegal relative to the laws of land, but illegal according to JW "laws" or doctrine.
According to JW doctrine, The FDS is God's channel of communication between heaven and earth. Before the coup, the FDS was defined to be all the anointed on earth, and the GB was part of that group and merely the spokesman for the group - individual GB members having no more authority than non-GB members of the FDS.
However, a few years ago, the GB, independently of the other members of the FDS, decided that it alone was the FDS. That, to me, was an illegal overthrow of the body (FDS); it was a coup.
Suppose the U.S. president decided that he has all power, and that he removed the powers of the U.S. congress. That would be illegal according to current U.S. law. He couldn't do that without the approval of the congress.
The U.S. president's doing that would certainly make it easier for him to enact his agenda because he wouldn't have to answer to or get input from congress. And the GB's removal of "power" from the other partakers makes it easier for it (the GB) to enact its agenda. It no longer has to worry in the least about what other partakers think; they now have no more authority than a microphone-carrying, pimple-faced, MS wannabe.
I'm sure that before the coup, the non-GB members of the FDS were a thorn in the side of the GB. They were probably writing letters, asking questions, offering unsolicited input, etc., and the GB wanted to stop all that, so it searched for a way to claim all power for itself. And you know how JWdom works; the org has a need, so it finds a scriptural passage or a scriptural account to back up its need. (In other words, the scriptures don't lead the org; the org leads the scriptures.)
The org found its scriptural backing and there was "new light". I think the GB's coup was a really profound event in the history of JWdom; it was a centralizing of power and authority - making the org more authoritarian. More power in the hands of fewer people is often, to me, not good.
I call on all elders to call the GB into a judicial hearing. The GB is guilty. It could not "demote" the other partakers without consulting with them. The GB went against JW doctrine in effect at the time.