The actual reason is that sysadmins don't have arcane requirements of what you can install in your Docker images. It will continue to be popular until sysadmins

The actual reason is that sysadmins don't have arcane requirements of what you can install in your Docker images. It will continue to be popular until sysadmins accomodate developers, or until the sysadmins catch on and start restricting docker environments. Ok, that's kind of cynical, but still true to a large extent if you ask me.