My own personal opinion is this.
People can only believe an impossibility if they really strongly desire it to be true.
It is an emotional belief rather than an intellectual and rational one.
JW's were (and still are) emotionally starved people.
They aren't really permitted to cut loose. As a consequence they are deprived of essential feeling, passion and fervor in daily life.
Everything you've been postponing that is meaningful in your life is right in front of you within easy grasp!
So, JW's went totally berserk FEELING the passion, excitement and adding the element of mass hysteria to their cold, drab, lackluster lives.
But note: Intellectually and rationally....NOBODY could believe it would really happen!
This is pure cognitive dissonance: holding opposite beliefs in your mind simultaneously.
It is like children playing an exciting game they both know to be make-believe. When it's over--it's over. But--while the game is being played out the exhilaration is too good to spoil!
That, to my way of thinking, is the reason so many people simply shut down and didn't budge from ground zero when 1975 came and passed with a deafening silence.
RATIONALLY everybody knew it would never happen. It is too goofy. It is (as Alan F is fond of saying) cartoon logic.
The 6000 years of Human Existence was played up to be something vital, significant, imperative, life or death by the Watchtower Society and they can never deny that. What is totally refuting to their present stance is that the significance cannot NOW be stated in any fashion which doesn't explode in their faces.
Why was it played up and played out by the Society if it really amounted to less than nothing. Never to be mentioned as even a noteworthy significant event in the Society's past!
WE CANNOT LET THEM GET AWAY WITH BRUSHING THIS OFF LIKE SO MUCH LINT.
Why did the Watchtower promote a non-event? Why?