I agree, poppers, but the manufactured reality each of us has is our primary survival mechanism. It is for that reason we might be reluctant to let down our defenses to allow in strange and wonderful insights. I think, to give a practical example, most people don't leave the WTBTS because they are afraid to allow in thinking that threatens their utopian paradigm.
Yes, a survival mechanism for the body/mind, but that survival mechanism is misconstrued to be "what I am". In other words, an identity is created out of thought forms that get labeled "me", but when that "me" is investigated it is found to be nothing more than a series of thoughts and ideas. People live their lives not from the reality of what they are but from and through the false reality that is created out of thought.
This begs the question, "Who/what am I really? If I am not the 'me' that I think I am then what am I?" Finding the answer to that uncovers the reality of "what is" that exists prior to any thought. The appearance of the world "out there" doesn't change when this happens; what changes is how that world is experienced based on knowing the truth of what one actually is. Knowing the truth of what one is reveals how utopian ideas only help to sustain an illusory world, and that is what is so scary to the "false me". The biggest fear that the false me has is facing the fact of its nonexistence as a real entity - it will do anything to maintain its illusory existence, including creating utopian ideas to hide out in. The WT has created a wonderfully utopian world for that false me to hide in. Is it any wonder that that world looks so inviting?