Simon, you hit the nail on the head. JWs don't become apostate overnight. Since I've just mentally come out, the experience is fresh in my mind. I've had plenty of people, apostate or not, try to rationalize against my beliefs. I could rationalize certain things, but JW propaganda thoroughly discouraged me from viewing or reading any blatantly obvious apostate material.
The change for me was this forum and sites like JWFacts where I was in control. I was in control of how much information I read. I was in control of verifying facts and references. Unlike videos where someone leads you down a specific path, these websites allowed me to quickly focus on what was important to me due to excellent organization, search functions, and interaction.
Having the feeling that I was in control of what I learned is what led me to explore my doubts and is what led me here.