Of course in Smalltalk, you do work with code-as-text, but then it becomes code-as-program (technically byte-code, with among other things a text representation). Does seem more reasonable than the anachronistic insistence on text->parse-to-AST->(whatever magic, and however many transforms the actual compile-part is).
Then again, we all know what a rich editor is. It's MS Word. And MS Word eats documents and depricates file formats.
On the other hand, I think Emacs Org-mode, Gimp images and the literate editor in Python, Leo[l] are examples of more pleasant "rich format" editors. It is a bit odd that what we take for granted for image files (edit history, binary format++) we fear in our IDEs.
See for example the Lisp 1.5 manual. Appendix E describes the handling of images:
> Overlord is the monitor of the LISP System. It controls the handling of tapes, the reading and writing of entire core images, the historical memory of the system, and the taking of dumps.