Do dystopias cheer you up?

I have been thinking a lot lately about why I like dystopian fiction.  Dystopias are so much more than the opposite of utopias.  I mean they have to be, right?!  Who would choose to read about "an imaginary place where people lead dehumanized and often fearful lives," as Merriam-Webster describes it, when we could read about unicorns and rainbows and endless supplies of chocolate?  Though I don't think there is any one reason that people like these stories, I have to agree with author Meagan Spooner that dystopias "...highlight the flaws in our society and extrapolate them into the future, imagining what our world could become if we don’t repair the cracks now while we still can".  One of the most disturbing "cracks" at present is the rise of incurable, drug-resistant diseases, although historically speaking, I guess ebola and MRSA are no worse than the bubonic plague and polio. Alexandra Bracken's new book, The Darkest Minds, imagines a world where an unknown virus starts wiping out children all over the United States (I'm kind of happy it wasn't some third world country for once!). 
The rest of the world refuses to allow Americans into their countries, and the government, unable to find an explanation or cure for the disease, cannot maintain order or keep the economy going and is soon replaced with military leaders and a brutal secret police force. One important thing I forgot to mention?  A handful of the children survived, and Ruby Daly is one of them.  That's good, right?  Well, not when all the survivors have psychic abilities ranging from photographic memories (the Greens) to controlling people's minds (the Oranges) to...no one really knows what the Reds can do but we know it's NOT GOOD.  For six years, Ruby has been imprisoned in a "rehabilitation" camp where a paranoid government has basically made slaves of the surviving two percent.  When she is unexpectedly freed at the age of sixteen by a group of domestic terrorists who want to harness her abilities for their own benefit, she pretends to agree with them until she can break away.  She meets up with a couple of Blues and a Yellow who are searching for a East River, a youth sanctuary that is so hidden it may be mythical.  Of course, not everything is resolved in the first book of a planned trilogy, but there is enough that you want to know how Ruby and friends survive in a future world without unicorns, rainbows OR chocolate.