People sometimes act as if there is a prescribed way to "install the agile" within their organization, but the truth is, adopting agile across the organization is a culture change.
We can talk about being prescriptive so people have a framework to operate within and rules to abide by, but while they learn the "muscle memory" of going through these new agile motions, how do we insure they're getting the benefits? I've observed teams that aren't continually improving; they're unwilling to experiment with the way they work when their current practices are working. There's no drive to do more, do better, and innovate.
The path to agility--to transformation--is dependent on people. We must never forget that because we must talk to people, often one-on-one, to coach them through transformation.