Greetings Jeremiah,
No wonder the saying 'never discuss religion or politics.' As already stated about JWs, theirs' is a conditioned response. No matter how politely or sincerely a question is posed, it provokes disapproval as it is 'matter out of place.' In WT Land, there is no tolerance for mavericks nor any mechanism for understanding one's personal motives. Such individuals emanate danger. [thoughts from an article on millenarian belief systems and how they pose difficulties for modern families (source forgotten)]
More on the source of cult thinking, whose presentation is often intelligently and logically proffered, such as I inferred from your mother's response: The ultimate desire of an intelligent cult is to combine absolute authority and infallibility with the power to learn from false prophecies and bad dealings; the Mother organization wants absolute authority AT ALL TIMES. [www.reexamine.org/wtobserver]
Only God can remove the scales from the eyes; your approach is that of giving a response for the hope within you, but doing so with mildness and deep respect.
Your friend,
CoCo