My apologies, I meant relevance to the problem that Docker solves, which is enabling developers to neatly specify and package their dependencies. I am not trying to diminish jails and zones usefulness to system administrators. I'm just saying if you put Docker in a comparison list to other technologies, jails and zones wouldn't even be in that list.

The annoyance comes from system administrators looking at the set of technologies inside Docker and saying "we already have that", and then just assuming Docker must be some sort of marketing scheme. I deployed docker in my organisation within a week of its first (beta?) release, when all of its "marketing" was a single blog post.

Docker solved an enormous real problem in the software industry, even if from a system administrators perspective it's just a new way of packaging applications, as there have been many in the past and probably will be many in the future.