speaking from experience, it comes down to this. the people with a critical eye to all this stuff (like me) don't have access to the big picture. I can only speak to the stuff I've worked on personally, and it doesn't add to what people are telling us.
Conversely, the people who *do* have access to the bigger picture stuff, have no vested interest in giving us the unfiltered truth (or any truth at all), so although they're in a position to know that's actually happening a little more clearly, we have no reason to believe that they're telling us anywhere near the truth of the matter
(remember, Mandiant told us the Chinese Sky Is Falling for *years* before they finally decided to 'show their work' with the APT1 document, until that point, their whole proof was "Trust us, we see more than you do". The government wonks take the same approach.)