>It's just that it isn't a crash course, or a course of any kind for any meaningful meaning of "course".
It absolutely is a crash course, for the most common colloquial definition of the term "crash course," although in a very nitpicky fashion the blog entry is not a "true course of study." The reality is when people say "crash course" in common English they almost never mean a formal course of study. Usually it's used in the context of someone needing to learn something quickly in order to do something else. A professor might spend 10 minutes at the beginning of a class doing a "crash course" on binary arithmetic, because it's needed for something else that's on the lesson plan for the day. Such a crash course might have no exercises and no materials whatsoever, but nobody reasonable is going to object to the term.
The blog entry is focused, brisk, and thorough, the key elements of a course intended to be completed rapidly for a specific purpose. Does it fail to fill a learning gap that clojure needs filled? Probably. But that doesn't make it wrong to call it a crash course.