As discussed elsewhere in this thread, acceptance of open source is very much an agency-by-agency deal within the DoD. IC orgs have pretty wide latitude to do what they want and NSA even more than others because of the primacy of their mission. Accumulo is widely used within the IC so it was to NSA's advantage to let it out - no doubt they did not want to maintain it themselves. Many orgs don't want to take on the burden of maintaining something, especially in the current budget climate where they'll have to go fight for $$$ and probably drop some other mission to make room.