I'd say that the post very accurately describes the problem of self-esteem based on comparisons with others and/or current trends. Which is a big problem indeed.
However it's a problem only partially connected to Impostor Syndrome, which is defined as an inability to attribute own success to own competences. People suffering from IS attribute their success to luck or "faking".
You're right. At no point did I make that assertion, however. The blog's posts are entirely about software development so the post was aimed at the audience of the blog.