Have you tried our vim-mode package? It's not perfect yet, but it's getting closer. It's built around an op-stack and is designed to be compositional. We definitely understand the points made in this article, and it's very possible to implement modal editing in a package. Extensibility vs compositionality is a false dichotomy.
I've tried atom with vim-mode, and it's not enough to replace either vim or emacs-with-evil-mode in my toolbox, not even close.
While the vim keybindings and modes in the editor are ok, it really lacks the keyboard-driven window and panel control you have with vim. Basically, the UI still needs to be driven with a mouse, which totally breaks my workflow. As another commenter put it, vim-mode is a bolt-on, rather than an integral part of the editor.
I certainly don't think it's a dichotomy; I explicitly want an editor that combines composability with extensibility.
And while vim-mode is impressive, I don't think it's really quite enough, unfortunately. Because the problem is that vim-mode isn't core to Atom's design philosophy, it's a bolt-on that tries to import a different philosophy to Atom. Other extensions (and native commands) don't expect to be in vim-mode and don't natively work in a way that extends vim-mode.
Like `evil` for emacs. The predecessors of evil (vimpulse and viper) did not cut it for me; but since evil I could not resist the switch.
I like the atom effort, and I think it may come a long way. But it also still has a long way to go until it is as mature as emacs.
Another good thing of emacs that I only recently started to appreciate is LISP --the grandpapa of all dynamic languages-- that is used for both emacs scripting and config-file format (they are kind of the same). JavaScript, how ubiquitous it may be, will never be as "impartial" and "timeless" as LISP.
The good thing about JavaScript, however, is that it has become a compile target for many languages. You could theoretically write an Atom plugin in any language that compiles to JavaScript, even a Lisp-based one like ClojureScript.
