I also like what I see every time I visit Racket but the fact that I'm not aware of any other project except Racket itself which uses the language and tools gives me the odd "why is this not more appealing - what's the hidden catch" tingling. Even OCaml has several fairly well known programs people use.
1) People's perceptions that Racket is an educational program
2) It's hard to communicate the unique qualities of Racket. "Racket is a full-spectrum programming language. It goes beyond Lisp and Scheme with dialects that support objects, types, laziness, and more. Racket enables programmers to link components written in different dialects, and it empowers programmers to create new, project-specific dialects. Racket's libraries support applications from web servers and databases to GUIs and charts."
A programming language for programming languages isn't an "Oh I get it right away.".
1. This perception comes from the fact that it is heavily used as an educational program. That there of course nothing bad about this.
2. The text you quote precisely communicate what Racket is: a language marketed like a programming-language research toolbox and not like a day-to-day programming environment. I don't really think that Racket developers really try to sell the language in the same way Scala or Clojure ones do.
Also, a lot of people actually "get it", and choose not to use the language.
