I wouldn't say that's the author's contention, very much the opposite from the way he passionately defends his work and authorship, as well as all the work he puts into researching very niche topics.
On top of that, citing previous work is one of the most important parts of research, and plagiarism can be a career ending move. In this case the author's blog comes up in the first google results for that research topic so it doesn't seem to be a side-effect of some emergent industrial system that would strip and remix knowledge with no regard for its authorship as much as wilful scientific misconduct (allegedly).