But there's another question to ask: why now?
Personally, I think it stems all the way back to the acceptance of fantasy among teen readers. I don't know about you, but when I was in high school and college, it was sort of looked down on to read fantasy, especially MG/YA fantasy, which was considered "kids' books." I remember book shopping with my college roomie--she whispered to me, almost like it was a dark, personal secret, that sometimes she liked to read books from over there in the "juvenile" section. I'm not saying people were picked on or reviled for reading fantasy or "kids'" books--but that if you wanted to be "cool," you didn't.
That idea's changed. It started with Harry Potter and progressed through Twilight. Suddenly--overnight, seemingly--it became not only acceptable, but cool to read in the YA section, particularly reading the fantasy and paranormal books. When I told that same college roomie that I'd found Harry Potter and loved it, she playfully poked fun at me reading "kids" books. Not too long ago, she confessed her undying love for Twilight.
So, there's a lack of stigma over reading YA books now that didn't exist before--and specifically YA books that are, at least to some degree, speculative.
But then, why dystopia in particular? Personally, I think this tends to stem from what we're seeing in society today.
Look, it's a scary world out there. There are a lot of things to stress out about, and a lot of things to worry over. And for teens, much of that is outside of their control.
According to the Publishers Weekly article "Apocalypse Now":
Why now? Newspaper headlines about swine flu, terrorism, global warming, and wars in Afghanistan and Iraq are inspiring authors-and making kids feel uneasy.
Dystopia works exaggerate the future, whether it's a future world of tomorrow or a thousand years from now. And, usually, the main characters are characters who don't control their world. The government or the environment or just plain bad luck controls the situations the protagonist is in. Even so, the protagonist rises above.
It's a classic hero story. And who doesn't want to be the hero?
So, why do you think dystopia is so popular right now?