Maybe from your experience with one agency/department but the DoD is a BIG organization. But it's still a thing in most federal agencies. Some not as bad as the others.
Oh for sure! When I worked as a contractor I worked with many departments but even the groups I worked with didn't represent the entire department they were in. But it was a very common theme with every single one that I worked with.
I'd love to see some data on FOSS usage across the DoD but that type of audit is likely impossible.