I'm so sick and tired of hearing that Children of Men supposedly left something out. Do you need every little detail spelled out for you, critics, flaky audience members? I'm not sure it's inherently a flaw to simply emphasize certain details over others. In fact, it's part of the writer's as well as the director's job! If I could get a list of specific dystopian circumstances that the film doesn't cover which would've had some bearing on the momentum of the narrative, then I'll take those criticisms seriously.
Until then, if you want an essay on dystopia viz infertility, mapped out like a damned textbook, then go find/write one yourself. The film may have some inherent flaws, but so does Apocalypse Now.
Is perfection really what you want? Are these same harping malcontents the ones that made 300 a far more successful film? I can only speculate.
P.S. By the way, before you start, I actually quite liked 300 for what it was, but it's earned three times as much as Children of Men, is in possession of far less vision, and is riddled with many, many more inconsistencies, historical bunglings and unfortunate choices.
Semaphore: Wuthering Heights, The Franklin's Tale, The Merchant's Tale
Paraffin Station: Planet Funk
A Tasty Little Dish: The Magic Flute