> modular desktop environment that allows everyone to develop/choose the basic modules they want. For workspaces, windows, docks, and any other window arrangement and quick access features.

But here you are already assuming that all these developers want to have a modular desktop environment. Not everyone wants that, or workspaces, or docks or whatever.

So yeah, if everyone wanted the same thing, I guess we could end up with one desktop environment that covers everything everyone wants. But (fortunately), the world is more complicated than that :)