No, I don't think there was one reason. There are 119 recommendations, and it stands to reason that some of them have long lead times.
When you're looking at disposing of underutilized buildings, it's not as though there was a building sitting vacant. They had to figure out which was the best building to be in and consolidate departments and agencies into a building, which meant they had to retrofit or renovate those buildings.
Some of these recommendations have very long tails, so I'm not sure that there would be just one reason that oversight was no longer there.