So I was aware of their tours of duty, but I thought that was not a carrot for outsiders to come in, but rather a way to circumvent the traditional hiring process. Probably doesn't hurt that the commitment is temporary.

From what I understood, rather than go through the job listing process with position writeups, giving veteran and disability preferences, dealing with HR on the certification process, getting various new office reorganizations approved by congress (they literally have to approve each individual office creation) and so on, they simply got an approval for 200-300 "innovation specialists" (that's what everyone's job title is there) and then they can informally cherry-pick whoever they actually want without going through the red tape. The mechanism is like having a standing approval for hiring 20 French speaking translators at all times, since that's a specialized standing volume-based need.

Anyhow, guess my question was more about the author's motivation for not choosing to extend the tour. It wasn't really spelled out in the post.