Because all they're good for is literally giving the masses existential crises.
>uh oh, another asteroid is gonna pass by our planet and potentially blow up Earth
>whew it just flew by
>oh wait, our sun is expanding and it's gonna swallow the Earth
>ok we migrated to Mars, no problem
>oh shit, the sun is gonna die out and we'll freeze to death
>we have to migrate to another solar system
>oh no another asteroid is gonna destroy our new home!
>fine, we nuke it out of its trajectory
>what's that? there's a black hole sucking us in and there's no escape?
>clutch hyperspace warp at the last minute
>sigh, we did it! we survived all these deadly cosmic events and now we're sa... w..wait... what's this?
>oh no... it's.... it's the fabric of spacetime expanding... it's tearing our molecules apart...
>ohhhh ahhhhhhh NOOOOOOO ARRRRGGGHHHH I.... AHHHHH IM.... IM FISSIOOOOOOOOOOOOOOOOONINGGGGGGGGG
