The book says that that's exactly what it's supposed to be, to inspire people to talk about it. But (also from the book) the war games the USA runs around these situations always end in a massive nuclear exchange. Sure, some specific situations, like the Devil's Scenario, I would imagine might not reflect a real war, but the case the book is making is that reality is far more likely to be closer to the worst case than to a "best case" (whatever that means here).