Back in the earlier years of the WT, people would get together and discuss their thoughts about various portions of the Bible. Some new thought might seem so astute that one would write a letter to the Society to share what they had found. This was gradually squelched and a "wait on Jehovah" mindset took root. This promoted a lazy and suspicious congregation that frowned on the thinkers.
So the religion not only drew limits on individuals, they drew limits on themselves!