I believe it's not just JW's who are kept in the dark about the Bible. If we all knew how the Bible came to be, how the canon came to be, et cetera, not many of us would consider the Bible an inerrant or divinely inspired book. Many people would no longer believe in Christianity, and the rest would need to say that "something" happened but that something isn't well described in the accounts we have. Maybe that's why we never learn where the Bible comes from unless we dig a little deep.
Can you imagine a "Bible Study" that began by probing who wrote the Bible, why, et cetera?