Over the years there have been a few news stories about some "crazed" JW man or woman that kills their family because they don't want them to be destroyed at Armageddon.
WTS teaching is that anyone who dies in this system, if not irredeemably evil (Hitler), will be resurrected in the New System. WTS teaching is also that those who are not evil but merely indifferent, disfellowshipped, children having unbelieving parents, etc., will be destroyed very soon, and that this destruction is permanent, with no hope of resurrection.
Since this is the case, it is in fact the greatest act of love to kill one's loved ones NOW, assuring them of a resurrection and absolutely preventing them from destruction at Armageddon.
Why don't more JWs take this obvious, foolproof route to protecting the eternal lives of their loved ones? I say that deep down at the subconscious level, most of them don't really believe it.