Oh, you properly identified and raised the bug? From the comment, it sounded like you abandoned ship and installed Fedora (which may or may not eventually have the same bug).
What? Yes dd absolutely is a disk writing tool, although that is not the only or even the tool's intended primary purpose.
It is useful for generating serial IO for a variety of purposes. For example, writing data with specific target block size; allocating contiguous blocks for use by an application (be it zeroing out a thin LUN before partitioning, or a file system); or simply dumping the content of one device to another (or to a file).
Good luck stretching out a thin LUN or creating an empty file that allocates contiguous space with cat.
If they say "we don't allow it" in regards to protected speech, it's roughly the same as peeing into the wind. lol I agree with you about everything else, there was no real need to call them out for this one.
Not to mention that they can't legally stop a "docker sucks" site or "@dockersucks" twitter account because that's protected speech, has trademark exemptions, and years upon years of case law backing the protections.
The title should be corrected to read "How to set up and deploy a 1000 node botnet". There's no mention of securing the hosts or the swarm what-so-ever.