The article says these are mostly web servers, probably located in data centers. Home users would not be interested in a pirate copy of the type of software offered by this company.
However, it is true that there are many slovenly individuals who rent servers in data centers. You can get a virtual root-server for $14.99 a month nowadays.
I think buwaya was trying to make the point that since home users of Linux download many free apps from just about anywhere, whose to say this type of virus isn’t hidden in anything else?