I had a similar exchange with my mother, but I aimed my responses in a very different direction. I don't argue, I agree and draw inconvenient conclusion for them. Such as:
JW - It's your fault, you didn't need to pioneer, you chose to, but could have been like other brothers who don't [put the Kingdom first]
Me - You are so right. I was a stupid and gullible child to believe their promises that the world was so soon to end in the 80s, because of their generation prophecy that has long expired.
JW - You have to use common sense! Don't just do what you are told.
Me - Maybe if Watchtower, the COs, and the assemblies would have put more emphasis on "common sense" and less on obedience, I might have thought more clearly and would have made better decisions that I don't regret today. Now I've finally learned not to just do what I'm told.
JW - You made the problem for your self by taking what people say too seriously.
Me - And that's a problem I don't intend to repeat. I have come to realize that the advice I've followed in the past is nothing but a big joke. I take nothing from WT publications or platforms seriously. It's very clear that anything written or said today can very quickly become old light in next month's WT study article. How can it be taken seriously anymore?
JW - No one said you can't go to university.
Me - You weren't there when I had my first bethel interview. The bethel heavy I spoke to told me that college was a waste of time since the end was so close and that my attending college would call my father's qualifications as an elder into question. How often I've wished that I could go back to that moment and get the counsel you're giving me now. He was just a foolish old man pressuring me into a course that would lead to disappointment, unhappiness, and free service to WT corporation. Now I've well outgrown the authority of my dad and the guy from that bethel interview is dead by now, so it's a fine time for me to go to university. I appreciate this encouragement you've given me to continue my studies and not look back at the mistakes of the past. You're so right that I wasted decades mindlessly believing things that I shouldn't have taken seriously. And I highly encourage [insert name of local JW teen here] to take education seriously and consider going to university.