I don't even think he fully misunderstands the content. The "Death metal lyrics and themes, while not to be taken literally, celebrate the outer extremes of human experience, such as the motivations of serial killers, the activities of the walking dead, death itself, and isolation." part is pretty accurate (although I would have added the words "detached from social reality" to the phrase "celebrate the outer extremes of human experience"), as is most of the rest of it. The part about empathy and ostricization from society is the part I have an issue with.
The list of bands is pretty shitty, though.