Somewhere in the middle, say point W, the image leaks and you wind up with the POTUS phone being tapped by Russia. Or by terrorists. Or a wanna-be POTUS assassin. It's worse than Pandora's box - once we open this box we will never be able to demonstrably prove that attempts to close it have succeeded, just like Ken Thompsons "cc hack"[1]. If and once Apple makes this image every Apple user on the planet, including the government, would be perpetually weary of it.

Basically, lim(consequences) = no guarantees that USA secrets are actually secret. If they can't keep the lid on one employee (Snowden) how on earth could they trust themselves with something this dangerous? 'Z' is inevitable.

The wording/example that Apple used really appeals to the common person, but you need to frame it for the government if you are talking to the government.

[1]: https://www.win.tue.nl/~aeb/linux/hh/thompson/trust.html