your title's qualifier "Spielbergesque" sorta answers why. you can make a movie about them, play with cgi/prop toys.
you have the ability to not blame anyone for that disaster. who do u blame earthquakes on? you can highlight heroes without having to worry about any foes. good and evil...except its "oops" and good.
hunger for example...well nothing you can make a movie script about, and when you ask "why", you get a terribly ugly answer no one wants to listen to...and maybe even human beings can be pointed at to be the "Fault". there is no fast moving famine, no blazing hero of justice or compassion....
as far as news focus, same thing. for some reason a story that is just depressing with no easy "Fix" or path to recovery is simply...well its depressing with no facts or points of view to pivot on to interest people with something dramatic or poignant.
ever discuss your point of view with a group of people and depress them, watch their eyes glass over and change the subject to something "lighter"? in media thats called changing the channel/moving on.
i have no idea, but i am tired of seeing things that are "too depressing" being ignored simply to avoid making the self involved person "sad" :(
I think the 60's movie 'Farenheit 451', was a good example of this mind set. Everything reminding us of the ugly, cruel, mean, dirty, scary, unequal, etc part of 'reality' are deleted, including books. Knowledge is controled by the state, 'for your own good'. Education is by memorization. Entertainment has been homogenized. Anything that could make you 'dissatisfied' is controled to maintain a stable socialization and acceptance of the statis qou.
I think quick-happening catastrophes have a way of engulfing us and offer an end in sight. Their urgency is intense and can hardly be ignored. When it happens slowly, well let's consider the example of the frog and the cooking pot.
If you heat an inch of water in a stew pot and heat it till it's very warm to the touch, then drop a live frog in it, the frog will quickly hop out. If you put it in a pot of cool water and slowly raise the temperature, the frog will slowly cook to death. (I've heard this example many times and really don't know if it's true, but let's assume it is.)
A more practical example: Nuclear accidents happen very seldom. However, many people are very fearful of nuclear accidents and so it's very difficult to site and build any more of them. In the meantime, we are slowly killing our planet with fossil fuels, including coal used in power plants. The smoke generated by these plants contributes to killing people as well. We really need cleaner energy and nuclear energy done right can be considerably cleaner, but as long as there are the occasional disasters, our fears will be fed and we will do our best to prevent the construction of nuclear plants, relying instead on the coal which is slowly killing the planet.