The Da Vinci code is a great movie, but I couldn't help but see some similarities between the Holy Grail and the Watchtower Society.
For those of you who know nothing about this movie, the Holy Grail is not a chalice but a woman, Mary Magdalene, who supposedly was Jesus' wife.
As the story goes, this secret had to be hidden by the Catholic Church - for if it had been proven that Jesus was married, the source of Papal authority would have disappeared. Descendants of Jesus living today would have had their DNA matched with that of Mary Magdalene.
This is all fiction, but the similarity with the Watchtower is this:
1914 is the Watchtower's most important date. 607 BC may be even more important. For without 607, there is no 1914 and therefore no testing time and Jesus does not select the Watchtower as his faithful and discreet slave.
I think GB know this, that their sole authority rests on a house of cards and that should 1914 ever be publicly exposed, they will all scream "apostasy" and run.
Therefore they disfellowship anyone they perceive as a threat to their authority.