The implementation of Clojure itself is not idiomatic nor is it intended it to be so. Most of the complexity in that example, for instance, is to deal with chunked lazy sequences. In user-land code, chunking of lazy sequences is pretty much a pure performance optimization that you don't have to worry about.

Granted, it's not a ideologue "turtles all the way down" LISP. But it isn't intended to be. If you want that, I advise you to find an old Lisp Machine and use that.