That might be because you've left out CIDER, which is
1) the most popular Clojure programming environment
2) solidly documented
3) built on top of Emacs, which is in itself very well documented (Just the reference manual of the vanilla Emacs is 500 nicely written, if dry, pages)
4) very featureful.
I guess the biggest problem is that most people are not familiar with Emacs, and not willing to read any documentation and guides.
1) the most popular Clojure programming environment
2) solidly documented
3) built on top of Emacs, which is in itself very well documented (Just the reference manual of the vanilla Emacs is 500 nicely written, if dry, pages)
4) very featureful.
I guess the biggest problem is that most people are not familiar with Emacs, and not willing to read any documentation and guides.