As a happy Docker user with a lot of respect for what Docker has achieved, what concerns me is that Docker is clearly an enabler for people to totally abandon proper release and dependency management along with sane sysadmin friendly configuration.

I can't tell you the number of times I've hoped to use a public docker image or just the Dockerfile, only to spend hours futzing with it because I was unhappy with the grotesquely insecure configuration or because I needed to work around a bunch of assumptions that are invalid once I've tuned the Dockerfile for my environment.