I don't see where admin accounts were created, merely local user accounts. Perhaps you see something I do not?
The ZDnet article, and almost all of the coverage of it, failed to mention a very critical point: anyone who wished it was given a local account on the machine (which could be accessed via ssh). Yes, there are local privilege escalation vulnerabilities; likely some that are "unpublished". But this machine was not hacked from the outside just by being on the Internet. It was hacked from within, by someone who was allowed to have a local account on the box. That is a huge distinction.