I think their blog being hugged to death is a good example of how this technology (read: web backend tech in general, not containers) is still too complicated for people in general to use it for simple cases, like scaling the load of otherwise static content. (It's wordpress, but still) We need solutions that require less resources and smaller learning curves.
It looks like this is true for Docker which seems to be hosting it themselves instead of using Wordpress.com
» nslookup blog.docker.com Server: 192.168.86.1 Address: 192.168.86.1#53
Non-authoritative answer: blog.docker.com canonical name = blog-1556129762.us-east-1.elb.amazonaws.com.