That makes sense, but in this case the blog was hosted on Tumblr. Free, no need to worry about vulnerabilities, and virtually no spam.

I wonder if there is a simple open-source tool that can convert WordPress blogs into static sites for archival. Like, just crawl the site, save everything as static HTML, and write some .htaccess rules to replicate WordPress's permalink structure. Everything will remain exactly where it was, except there won't be any vulnerabilities and you can't accept comments anymore.

But I suppose the author really is the kind of person who likes clean desks -- the kind of person who cannot stand the sight of no-longer-maintained things being scattered around his part of the Internet. (cf. SoftwareMaven's comment about virtual hoarding above.) If that's the case, I can understand, because I'm a bit like that, too.