Great write up , I totally agree on this.
The power in a modular system is much greater than some think.
I believe on the hardware side of things it would be easy enough to create modules for certain purposes, some of us here already have that going , being it for personal or very low group use.
Software would be much harder , some prefer windows other mac , and then we have android tablets on the rise.
If we, as a community can agree on a standard we can start development.
It would be so much easier for so many people if you decide you want a certain functionality, to look up the hardware , buy it or built it , and have a module for the general front end ready for download.
Development of plug ins would be much more, as there would be only one front end to develop for , same as support , more mind on the same thing in stead of on several different front ends.
Am I close to what you have in your mind ?