That's because when they are found out to be true, nobody calls them "Conspiracy stories" any more. We call them "scandals". (ref: "Watergate Scandal"). Note that the perpetrators were indited for conspiracy.
"it's too hard to coordinate all of these efforts."
You're doing it wrong.
pay people to add backdoors
This is hard if you have the money? Done.
tell DARPA
When the FBI spooks go to the military contrator parties, who else do you think is there? If you know that something is tainted, you tell people who might return the favor.
start a marketing arm to convince people to use it
Why? It's free crypto. Done.
EDIT: A proper response to this kind of situation: http://news.ycombinator.com/item?id=2006694
I think a definition of terms would be useful. Cooperation is necessary for much of what one does. At what point does cooperation become conspiracy?
"It's a conspiracy, of course there is no evidence!"