This is arguing that Docker is "harmful" because the components it builds on existed before. That makes no sense at all.

Only when I got to the 5th section did it make some sort of argument, which ended up being about Docker not using an init system to manage daemons, and the usual problem this brings to badly-written images (process reaping). Ignoring the fact that plenty of daemon managers exist, and are used both with and without Docker, like supervisord.