Hypothesis:

The fascination with cataclysms, end-time scenarios, apocalypse etc during the late phase of civilization doesn't appear because people are more afraid of such events than usually, but because they unconsciously hope for the end to come.

They just can't take it any longer.

And who could blame them? Imagine another century or two of constantly growing corruption, incompetence, idiocy, degeneration, perversion, war, crisis, tyranny…