I really have a feeling that X11 is beyond "good enough". Embedded systems wanting to use Linux have mostly had to do their own solution (Android, qtopia before that) because X11 was to heavy.
Changing Screen resolutions on the fly (think: "projector being connected") still is a lottery, mutli-monitor support usually requires a lot of manual intervention, bad drivers still can cause X11 to crash and take everything else with it, there are still graphical glitches when the system is busy.
For years - heck - decades, Linux distributions have tried to make this work, but I think that we are now at a point where everybody agrees that it can't be fixed within the framework of X11.
So the question is: "is clunky behavior good enough? Is being forced to use completely different technology on mobile devices (= less code sharing) good enough?"
While the answer was yes 5 years ago, it's not longer true and that's why I'd give Wayland more chances now.
I really like Wayland and would like to see it succeed though.