I dream of a world where device manufacturers are required to hand the firmware signing keys over to the public X years after product going to market. I have a growing collection of no longer supported but perfectly capable electronics which are just collecting dust because they're locked down. The Vita is a prominent example of this - the hardware is amazing, but the titles are just not appealing and I'd much rather play some SNES or homebrew on it. Instead it sits collecting dust, neither providing any value to me, nor any revenue to Sony.
In theory everything you need is in those binaries. We had to start from nothing. There's already a lot you can learn from the device just by running your own code on it.
I have to admit I never done one myself (always been meaning to, never had the time) but a lot of friends have and I trust their words. I believe it helps in the real world because these "war games" simulate real world systems and trains people in attacking them (therefore learning how to defend against such attacks).
The fact that the author is essentially thanking Sony for securing devices against them is something I find a bit baffling, unless it's some deep sarcasm I'm not seeing, or thanks for not making it too secure.
There are those who reverse engineer encryptions, network protocols, and in this case hardware and learn more about the technologies used than anyone else applying for said job (just as an example). People learn invaluable things from this scene. Yifan Lu has done some interesting stuff, and I have seen others do great things that have led to their growth in the Reverse Engineering scene. Some go as simple as recreating a close sourced websites PHP back-end (or recreating it in PHP) and they learn plenty to get them started. The tougher the security the more you have to understand what you're working against, the more you learn.