The Docker team is doing more than anyone to move container technology forward, but orchestration is a much harder problem to solve than wrapping OS APIs. I wish they would stick to the core, and let others like the Kubernetes team handle the orchestration pieces. Swarm is hard to take seriously right now. I'm not sure bundling it into the core was the best way to handle it.
I disagree. Kube, Mesos, etc.. are all great I'm sure. I had Kub documentation open in the background for about a week or two while doing other things, trying to get a handle on installation, deployment, how it will fit my use-cases... I kept wanting to dip in, but kept getting pounded by tons of heavy dependencies I would have had to learn. After Swarm Mode was released I had a cluster deploying things locally within 2 hours of reading the documentation. From there was able to map all of our use-cases on top (rolling updates, load balancing, etc...). I totally get that it's "hard to take seriously" perspective with some of the early glitching, but Kube, Mesos, etc.. needed this egg on their faces to realize how easy the installation and getting things up and running should be. If nothing else, that alone will make those other products better.