Goodreads blog has a nice graphic timeline of the dystopian novel. The genre appears to have peaked in the mid-40’s, the mid-50’s, and well, now. The difference between now and the 50’s, according to the graphic, is that today’s swath of dystopian books aimed at teenagers features more romance, is inspired by the “vapidity of pop culture”, and is rated more highly by women than by men. That’s probably because zombie apocalypses are notably missing from the timeline.
The Finch and Pea 