Terry,
I understand your point. In a perfectly rational world your point would make perfectly rational sense. That is not the kind of world we live in, however.
In the world we live in a great many people put a great deal of confidence in things they believe the Bible teaches, whether or not the Bible actually teaches them. As an example, "When the end comes you will not know the changing of the seasons."
What this tells us is that people who put trust in the Watchtower Society/Governing Body often do so believing that (a) the Bible is the word of God, (b) it contains instructions for humans, and (c) that the Faithful and Discreet Slave class (nom de plume for the Governing Body of Jehovah's Witnesses) is accurately teaching them what the Bible teaches.
It may be that ideally none of that would matter. Perhaps none of it should matter. However, the fact is that it does matter whether the Governing Body is teaching people what the Bible teaches. This matters whether or not what the Bible teaches is something that should be regarded as meritorious by anyone.
That is the basis on which Grissom launched his ill-advised thread. He claims the beliefs are Scriptural. He is wrong. It matters to prove him wrong because an awful lot of people follow the organization solely because they believe the same thing Grissom believes.
If he doesn't care about prophecy, false or otherwise, discussing it would be moot. If he cares about doctrines and practices, discussing it might be fruitful.
