Agreed. I frequently mention Code Browser (http://tibleiz.net/code-browser/) which has multi-level folding that works very well. When I work solo on a project, I tend to fold many levels deep and create what would otherwise be a "smell" but it doesn't seem to cause problems. Unfortunately, I can't use it when working with a team because I know of literally nobody else who uses the editor.

I've considered writing a plugin for LightTable or perhaps Sublime Text but I have no experience with either of their API's and I am not sure whether it would even be possible.