I think a lot of people naturally prefer dystopian stories. I mean, with dystopia, you've got a whole package of good story material. There's a universe that's engaging, a pretty clear-cut objective (i.e, resist the authoritarian government, stay alive, try to change the world for the better)... People are kind of grimly attracted to conflict. It draws upon a very primordial fear. Since the Holocaust happened, and several other things, our minds have been open to the utter atrocities that humans can create. You've got people being numbed and then incinerated alive in "Rootless" because they didn't meet the genetic requirements for a scientific study, Avoxes, terrifying booby traps, and a child gladiator fight to the death in "The Hunger Games"... Just, the idea of a dystopian society surreptitiously fascinates us.
I personally have a couple dystopian-esque film ideas that I'd love to do. Dystopian stories have just CAPTIVATED our society. In a way, it's kind of comforting to us. I mean, human society has almost always been pretty significally dystopian. It probably makes us feel better about ourselves to read about somewhere even worse.
Also, you know, a problem and a character dealing with it is one of the foundations of a story... Dystopian stories just blow this into HUGE proportions. That's why we tend to like them so much. They're also sci-fi, often pretty cool, have a lot of action, and have a tendency to lean towards the teenage demographic that we're a part of.