I don't get the fuss about Wayland and Mir. Like inventing a new mostly-incompatible subsystem is something new in GNU/Linux world. I mean, there were no "Linux way" ever - just take a look at zoos of sound subsystems, network management subsystems, init/rc subsystems and so on. GNU/Linux world is well-known for having magnitudes of software doing same things but in completely different ways, sometimes with some compatibility layers (like ALSA-OSS), but frequently completely mutually incompatible. This is not good, nor bad thing, it's just that there's no any established rules beyond fundamentals POSIX and FHS (and even those are poked from time to time), just more or less popular approaches.

GTK ran on DirectFB just fine, without X11 stack, so getting rid of X11 is nothing new. There were XDirectFB that worked as a X11 server, too. Not sure if the code's maintained and works now, though - haven't visited that land for, IIRC, about 5 years. Anyway, and I don't remember any worries about that.