Look at it from their point of view... they approach some developer and it's amateur hour. The dev might get stroppy, there's all sorts of infrastructure problems, they might not do it right... it's a mess.
But if they approach the CEO, it gets done right. The CEO brings in Legal, who promptly shit themselves. They bring in the CTO, who is told to shut up, sign this NDA, and work out how to make this happen as fast and painlessly as possible. No problems, the bad things get done, no-one gets told anything, all good. Shit continues to roll downhill...
Also, if you were an employee in a company in this situation, and you'd been told that the security of the nation depended on your silence, and more to the point, you'd be locked up and your career ruined if you went public, what would you do? Whistleblowers are pretty rare, because the consequences of doing that are huge.