I have my own personal viewpoint on why its often so futile to reason with a Jehovers Witness.
I think many witnesses, feel like legitimate children to the organisation. ( i have often heard the org being referrd to as mother). And this parental sence of belonging is so strong that new membets become " stepchildren". These stepchildren dont have such a sence of belonging or ownership, but seek approval and love from the legitimate children.
I am not sure if that makes sence? But i guess the life within the " lie" becomes more important than life without the " lie", where they dont have a sence of belonging and ownership.
your point of view is welcome.