The Pentagon has plans for a lot of weird stuff. Every once in a while something strange gets declassified, like a plan to invade Canada or the takeover of a NATO member state by the rest of NATO, and people act like this is something they thought would happen.
The military wants its strategy people to be flexible, to be able to formulate a battle plan promptly in the event of an unknown or unexpected change of circumstance. Having them spend their entire careers re-running the same few likely/plausible scenarios with slightly changing forces and weapons doesn't make them flexible. Having them play the world like a game of Civ with only the fun victory conditions does.
And, like Jason said: The less plausible their busywork actually is, the less likely people are to misconstrue it as a real plan.