For the tech enthusiast and the visionaries, you are correct; It is a very viable technology. However the majority of people that deploy software are rather conservative and unless they see a market leader such as Microsoft with a solution they don't deem the technology safe to use. This is well documented in a lot of literature like Crossing the Chasm but can be observed frequently if you work at a larger non-tech oriented company. Whether or not this notion is actually correct is debatable but it doesn't change the validity of it.
This also means a lot of Microsoft shops who have a lot of Docker enthusiasts will be able to pitch this to thier bosses, who might not have been on board prior to this since it wasn't an enterprise MS product.
I think that when a "market leader" finally adopts technologies that were in use for more than a decade by their competition, it's safe to assume the tech got mainstream...
