During talks that he and I have had along those lines, he essentially said that he didn't WANT to know. He said that this [JW life] is what he's done his entire life and he didn't know what sort of person he'd be without it. In a nutshell, he WANTS to be a JW and would prefer to ignore evidence that disproves WTS theory.
That is the sad, honest truth. One elder commented that if were proven that God did not exist he would still live as one of Jehovah's Witnesses.
Being one of Jehovah's Witnesses is a way of life and most who have spent the majority of their life in the organization are unable to cope with the idea of living with out it. Like many in our modern society, people want to be told what to do. Just like people who spend the years in prison, they are unable to function with freedom.
Inmates are told when to get up, what to wear, what to eat, when they can walk through a door, what they can possess. Such institutionalized people are frustrated with life outside prison walls. They literally get frustrated when ordering food at restaurants and some will wait for permission just to walk through a doorway.
The best way to help someone in the evil empire to decide to leave is to live your life the way you want to. Jehovah's Witnesses are taught that non-Witnesses are miserable and those who leave are even worse off. Prove the teaching wrong by living a long, happy life outside the organization.