I think tyydyy is partway there.
In order for a serious intellectual conversation to be effective in providing sufficient points of view for a conclusion to be reached, it has to have exposure. And it's easy for this exposure to be found in "main".
However, if those who want that kind of conversation all flocked to the other forums, as I do myself, and lived there, then that would solve the "problem".
I mean, the point of having a forum called "main" IS for general talk.
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The Watchtower, April 15, 1928, p. 126 "As every one knows, there are mistakes in the Bible "