Kool Jo, as far as your op question, I am not sure what it would take besides having an annual meeting that is hooked up to the congregations and the GB saying that the whole thing is a fraud. However we must approach reality.
In the 1960's my dad was a 1975'er, up until about 1973 and then he didn't see things happening like he thought in accordance with the Watchtower Bible and Tract Societies teachings and thought it would take a WEEEEE bit longer maybe 7-8 years.
The late seventies were somewhat difficult, there were still new ones coming in, which made all the old timers "behave", but people like my father were pretty sore with WTBTS and had written letters that were answered with "get your butt in line and tow the rope" verbage. I wish now they would have disfellowshipped him for his letters, but nothing was said by the congregation.
Through the 1980's and 1990's we were all expecting something within the 70-80 mark of the "generation" of 1914. But it never came.
Mom is still alive and is absolute that she will not give up her faith. However, she is not a humble women who would admit a mistake anyway.
I believe it takes a mature person who has humility to accept they have been fooled, "hoodwinked", taken, conned, etc. With many witnesses it crosses the social, religious, family lines and people will stay with their religious beliefs because of a perceived loss of family or social ties.