* Self-documenting
* Easy to dynamically inspect and change the editor internals and all packages, from the editor itself
* Emphasis on the editor as an interface into your system (the editor as a way to process and "glue" together text from subprocesses)
Atom in particular seems promising, but from the time that I spent with it, I quickly concluded that it was missing the spirit of Emacs entirely, because it was not straightforward or well-documented how I would go about exploring and changing the internals of the editor and its packages. E.g. a package was throwing an exception...it was quite a process to find the source, set a breakpoint on that error, and fix/work around the bug. That's trivial stuff in Emacs, and IMO is at the spiritual core of Emacs.
I would love to be wrong here, so please correct me if I'm mistaken!
Getting all of our tools into similar management forms ultimately makes all of coding more accessible.