What you just said applies to almost any business with more than 1K employees. I'd say any programmer considering a career at General Electric (random pick) is insane. It's a government job without government benefits.
I have friends in software development at military contractors in the area. Apparently, after you work for three years you get "tenure" and you receive France-style job security. Since its more trouble after that to fire you than to just pay you, the worst that can happen for incompetence is that you get left alone with nothing to do. Also, if you leave, you are always guaranteed a spot if you choose to return.
Nothing is good for job security like being removed from the discipline of the market. Hook up to the public teat and you can feed for life.