I understand your point but the problem is that the title is "Arch Linux AUR Repository Found to Contain Malware" (and not, for example: "AUR Repository Found to Contain Malware"). I would argue that the implication (I guess reputation-wise if that matters) starts with the "Arch Linux" part. It's easy to jump on Arch because of this regardless of the fact that the AUR is not supported. At a cursory glance plenty of people (though incorrect) will equate this to "Arch Linux contains malware"