It should and would fail if it were only about truth, facts, logic, reason, accountability, but as you have touched on already it's not. Many JWs don't care whether there is proof for this doctrine or evidence for that claim they just want to be part of a group, a community of people who think the same, talk the same, walk the same, dress the same, love the same "God" and hate the same things. Some people like being told what to do, what to think and how to feel or not feel.
On that basis it may never fail.