We have so many different Desktop "OS's" already. There's hardly a need for a _revolution_; strong stability and support is needed but there's just no paying market for it by the looks of it.
4 biggest desktop environments are by mega corporations (apple, microsoft) and by big open-source collectives (Gnome, KDE). But is that it? No, there's also a bunch of tilling-window managers with their own desktop philosophies, there are entire terminal drawing frameworks with full GUI support.
Desktop is awesome. If anything mobile is the one needing to catch up. iOS and Android are awful, awful environments outside of casual usage. Just try writing up a document on your phone! Just imagine what could be if they were on the level _desktops_?
Real question: Do we continue to dumb down software to exclusive casual usage for house-moms or we try to move our society to be more techn savy as we are clearly moving to a more tech relying world. Why shouldn't everyone know how to code?
To paraprashe Mr. Engelbart: it's a failed tool if you use it exactly the same way the day you bought it and a year after.