After the last post, I've been thinking about the reasons why a Jehovah's Witness would be offended when told that there is a difference between Watchtower doctrine and Biblical doctrine. And that they, when they are challenged, always try to defend the organization, while claiming allegiance to the Bible. I guarantee you that no one who truly reads the Bible in context comes up with Watchtower doctrine (and extra-biblical prohibitions) on their own. At some point a potential Witness had to be convinced in the Watchtower doctrines before becoming a Witness. Unfortunately, those who are most susceptible to Watchtower doctrine are sincere people who either haven't really read the Bible, or have read it poorly.
The Watchtower approach is unlike that of Paul in Scripture. When Paul entered Berea in Acts 17:10-12. The Jewish Bereans didn't berate Paul or simply accept what he said was true. They checked out the Scriptures themselves. The Bible then commends the Bereans for their attitude — saying they were of noble character because of this. Paul didn't get angry with them for not "getting it." or disagreeing with him. In fact, it seems that the Bereans had a high view of Scripture, and were very knowledgeable of the text. The Scriptures were held as authoritative even over the Apostles themselves!
However, Watchtower doctrine is dependent on a particular manner of interpretation (prescribed by the Watchtower), not on a plain reading of the text, and sound Biblical exegesis. A prospect must be convinced that the Watchtower interpretation supersedes whatever she has come to believe the Bible says from simply reading it. She must be led to believe that she has read the Scriptures wrong, and that hard to understand sections are correctly interpreted by the Watchtower. Once convinced, the prospect naturally follows the Watchtower's conclusion that the Watchtower is God's organization, and therefore speaks for God (feeding the flock at the proper time).
She will become confused between Biblical authority and organizational authority. She will be unable to distinguish between the two. That's why a Jehovah's Witness would never admit that they follow the Watchtower. In their mind they are only following the Bible. But it's on the grounds that their interpretations match with Watchtower doctrine.