Humans are violent, selfish, and stupid.
I'm writing this in 2016 -- I don't even have to justify that statement, right? Even without the election, it's been wall-to-wall mass shootings, war, racism, and tragic celebrity deaths. The violent, selfish, and stupid nature of people is why things are always getting worse -- the more of us you cram onto the planet, the more our spiritual toxins pollute the stew. It's simple chemistry. Haven't they done experiments where if you just isolate a bunch of strangers in a room for a while, they'll eventually turn on each other like animals?
Well, they actually did a much larger version of that, in which a million and a half of these violent, selfish, and stupid primates were piled onto a cramped, filthy island ...
... and based on what we know about people, shouldn't it only be a matter of time until that whole place is a charred, smoking ruin? Or a big pile of garbage and toppled buildings, like Idiocracy?
Yet, if we revisit those shit-flinging animals 150 years later, we find their island looking like this: