It's the lure of the myth of permanence. JW's have their natural reasoning flipflopped in favor of their aversion to impermanence. In other words, we know that everyone who has ever lived as died, and we will die also. Some persons try to get around it.. freeze their bodies in liquid N2 and hope for the future. Witnesses don't have that kind of money to throw around, but they want the same thing: immortality.
And immortality rarely has anything to do with quality of life. Look at how wretched medicine allows us to become, just in the name of living another day, making euthanasia illegal. It is just this grasping after what cannot be had. It's as natural to die as it is to be born, but Witnesses are corrupted into thinking otherwise. They are told that in fact dying is NOT natural for human beings, but is in fact the result of two distant ancestors eating some fruit a talking snake conned a woman into munching. That in itself should have thrown up big signal to us at some point. But it goes further. God had to make us Unpermanent because of the whole fruit thing, but he's made a way out of it, in some complicated formula involving a sacrficice (and if you get right down to it, Christianity really is a cult of human sacrifice) of God's son, selling Watchtowers etceter until you get to survive when God get's medieval again and kills most everybody else. But after that (and Armageddon's dissapointing sequal a thousand years later), you get to live forever, like you were supposed to.
And we put aside our wonderings about what the hell we were going to do for a trillion billion years eating fruit and living in the Southern Alps, playing Rummy with Brother and Sister Jones for the billionth time, or whatever they always paint Paradise as being. We put that aside, because we've already given up our sanity to this desire to never die. Some people come up with fantasies of colonizing the universe, not that that wouldn't be boring after awhile too. Oh look.. wow.. another nebula. Great. Wish I could have sex, but Jehovah lovingly took that away after Armageddon. Oh God I wish I could die.
But we put those thoughts away.