it's almost impossible for any person of conscience who originated such doctrine to do a complete u-turn and change it and still believe it when the passage of time has proved beyond doubt that doctrine is no longer credible.
"Often the less there is to justify a traditional custom, the harder it is to get rid of it." -- Mark Twain
Apog: I've generally leaned toward the school of thought that the leadership is sincere...Instead of admitting "We don't know how long a generation is", they've come up with a new definition of "generation" which strains logic in order to explain why we're all still here in 2014.
Interestingly, though, they did admit indirectly in 1995 that they didn't know the length of the "generation" when they defined it as basically an "era... But they were almost humble there!... on this one issue... for a period of 15 years.
Not only a major contradiction, but being "almost humble" is like being "almost pregnant". Either you are or you aren't.
If the definition of "generation" became a fuzzy concept WT sure wasn't letting on (despite the alleged 'sincere' re-thinking of the matter). WT has continued its relentless mantra that Armageddon is coming anyday now. In fact, at the last DC I attended (2011) the Bethel speaker said, "We are in the last days of the last days. The Governing Body really believes that."
Hardly a fallback position to "we don't know", and 'we'll just leave this one alone for now'.