When my children were little, they would ask a string of questions about anything. If you've have or been around little ones, you know what I mean. After a while you get tired of trying to answer the steady stream of questions - I would often finish it with the answer "just because" or "that's just the way it is"...
If you have questions about anything the WT puts forth as doctrinal change, the final answer will always be "that's just the way it is" or "just trust the GB" or "wait on Jehovah". If an elder is an honest guy, he might respond with "it confuses me too". But, ultimately, the final answer is "just because".
Most publishers are hook, line and sinker believers. And that's how the WT organization wants it to be - to inform and control people as if they were little children.