I totally hope that "Cognitive Dissonance" has its limits. I really, really, really do. And, I hope that there are large numbers of JWs who have limits and will wake up.
It does, but the nature of CD is that people typically double-down on the dissonant behavior before they begin to reason properly. Unfortunately, some never get past this. As John Aquila points out, usually a person needs to be affected personally, before they can shed the CD. Fear is almost always at the root of the problem, and they need to overcome that first.
d4g