It's not about realism, it's about trying to be Hunger Games: The Series under a different name.
BINGO!
I remember touring the Vatican and seeing tombs of popes decorated with gruesome skeletons and it turns out these were generally done during the times of the black plague. A lot of art of that period was very influenced by and heavily featured death as a constant presence. The art of the day reflects the times.
So what is big now? Looking at bookstores, TV, and movies it appears that there is a major trend towards dystopian futures, zombie apocalypses, cities in ruin, etc. Basically not an optimistic vision of the future. Consider as examples "The Walking Dead", "The Hunger Games", and this upcoming prime time network show. Four years into Obama and the mood of the people is not hopeful. Contrast that with the big films made in, say, Reagan's second term. Top Gun, Rambo, Rocky IV (the one with the rotten Russian boxer), Back to the Future, Coccoon, Crocodile Dundee, The Untouchables, Rain Man, Big, Batman, Look Who's Talking, etc. Generally upbeat movies with happy endings that held the USA in high esteem.
Interestingly, the undertone of most of these current dark films is that the world is going to hell and the government is either impotent to do anything about it or caused it. So at least that part is realistic :-)