I really don't see how an app that implements maybe 1% of all useful features a good editor has could compete for the attention of technical users.
The way I usually collaborate on things like papers / technical documentation is to assign specific sections, parts of the exposition to different people. I think it is rarely productive to edit the same part of the document at the same time, but I might be wrong or simply haven't found a use case.
Admittedly so far I have used Latex for serious projects, there you simply create a master skeleton file and then people work on different sections individually. The choice of editor then doesn't matter. Something similar could be done with org mode.
I've only used org mode only for personal note taking, todo lists and drafting documentation, but I would imagine it would scale fairly well to small teams using it.
If instead you had only said that YOU enjoy doing that, there would be nothing to disagree with.
Generally, I think it's a pretty good principle to refrain from making blanket statements about how other peoples' projects are unnecessary or whatever.
You can try the demo at sandstorm.io (install brainstorm as an app)
Or you can try a slightly older version here: http://brainstorm-notes.meteor.com/board/Home
Is that similar to what you're looking for?
Someday I'll build the perfect note-taking application, quote me on that!
http://www.knightos.org/documentation/reference/threading.ht...
https://github.com/KnightOS/kernel/blob/06aeba5442a073d02338...
Unfortunately I haven't extracted it for public consumption yet, but feel free to take a shot.