We're all talking modular this and that, bla bla bla....
Back in the day bikes didn't have derauleur hangers, remember? They had those little thingies that fit in the long horizontal dropouts that the derauleur hooked onto that kept in it place when you pulled the wheel etc... Is there any reason at all that somebody can't fab up a small piece that does the same thing in a track end? Small, cheap, and as effective as they ever were. Why is this a worse idea than all the goofieness and expense of modular dropouts? Not that I want gears, but still........