This analysis is spot on. The author is annoyed about the absence of many things that, in most programming languages, would be seen as outright absurd. People have come to realize multi-methods, monkey-patching, and mutable interfaces break down when writing code at scale, across a large team. It's no surprise that Racket has internalized these lessons, and someone in love with Common Lisp would see these as shortcomings. A Haskell programmer could similarly rant about Python's lack of closures, a C++ programmer about JavaScript's lack of templates, and so on. There are many reasons to hate many languages, but "that language isn't this language" is a rather petty one.