One of these questions where we, those doing the discourse, need to pick apart what the word "you" refers to here.
In this context, it is national governments, who have started to fear that there may come a day when they are not allowed to or able to or safe to run Windows. That gives rise to the question, "how can we get a system that minimizes the disruption of migrating away to Windows?"
Ultimately it's not about specifically wanting AD or GP as technologies, either, but the things they enable: seamless single-sign-on across an organization, and management of software security and updates across a fleet of desktops.
(possibly the thing that fills this hole is simply a fleet of consultants which go around explaining things to CIOs!)