Have you ever been annoyed by users of *nix systems that are less popular than Linux? Then have no fear; Wayland is an effort to kill off those platforms.
You see, first you reduce X on Linux to the sort of second-class status that it has on OS X. So then people switch their development for Linux to Wayland. So then they stop maintaining an X version of their app (even if the toolkit they're using supports both X and Wayland), since it costs them resources for such a tiny fragment of people. Then, since nobody's developing for X, the toolkits themselves drop support for X. And then all those people using *BSD or Solaris are up shit creek without a paddle. And then the makers of Linux server distros, who are the ones who have to compete with *BSD and Solaris profit.
Oh, sure, they can't come out and say openly that the purpose of Wayland is to destroy the competition. So they'll talk about all sorts of technical advantages. But then ask yourself, if the goal was simply to create a modernized/simplified/higher-performance/whatever GUI system, why deliberately choose to make it dependent on the Linux kernel, instead of developing such a system for all *nix systems?