Just like real life.
So, yeah, it was was high on verisimilitude, which can be artistically satisfying sometimes—and that was part of why I liked the film. You avoid the tropes of action hero movies when everybody dies at the end. It's refreshing and interesting, and an unusual way to have people be heroic.
But I can understanding turning to sci-fi as an escape from the depressing realities of everyday life (this is a huge part of my love for Star Trek), and it certainly doesn't deliver on that.
Another sci-fi movie in this vein is Melancholia. I adored that film, but (spoiler alert) literally everybody on earth dies in the end. It's a much more powerful film for that fact. There are plenty of films where everybody ends up happily ever after, so it's nice to have a refreshing counter-example. I say the same thing about Trek in reverse. Most of the rest of sci-fi portrays a dark future; I feel that Star Trek should preserve what makes it unique in the world of storytelling: namely, the portrayal of an optimistic vision of the future. Otherwise, it becomes just like everything else and has nothing original to offer. There is much to be said for originality in art—and in contemporary cinema in particular, originality and surprise are greatly under-appreciated qualities.