There is a little bit more to that story. Canonical had initially chosen Wayland to be the successor of X11. Then they dropped that plan in favor of the in-hous

There is a little bit more to that story. Canonical had initially chosen Wayland to be the successor of X11. Then they dropped that plan in favor of the in-house Mir project, citing problems with Wayland. The Wayland developers debunked all of those points, but Canonical just neglected the reply. As I remember it, it was this incident that irked a lot of people and gave Wayland the push to become what it is today. Wayland wasn't as popular before that.