Unlike the kernel, desktop development for Linux is done almost wholly by volunteers in their spare time. There aren't many paid developer seats for KDE, Gnom

Unlike the kernel, desktop development for Linux is done almost wholly by volunteers in their spare time. There aren't many paid developer seats for KDE, Gnome, et al. Bold new interfaces, new APIs, and complete reinventions of the desktop metaphor are really exciting hobby projects for these brave volunteers. Perfecting backwards compatibility, re-implementing buggy behaviour from prior versions, and ensuring ABI stability do not make exciting projects. These are the torturously painful, labor-intensive foundations of Microsoft's success.