GNOME and KDE are monolithic and encourage everything under their umbrellas to depend on everything else. The Linux desktop has fallen into the same pitfall that so many enterprises do: reaction against integration issues in a chaotic environment has led to monolithic approaches that provide uniformity and integration but prevent the mix-and-match flexibility that allows individual projects to fail and succeed on their merits. The monolithic approach, the architecture astronaut approach, means high commitment to each project and leads to projects like PulseAudio becoming "too big to fail" even if they fail at their technical objectives. The next step in evolution is supposed to be a loosely coupled services architecture that provides the best of those two worlds. I won't venture to guess where it goes after that.
however, I've noticed that striving for loosely coupled architecture has often fostered its own brand of, if you like, architectural astronomy, as the architects try to design the ultimate meta-framework that will make it easy to integrate disparate components without the components knowing anything about how they can be used.
