Intel and XMir

Actually that kind of bravado ^w success, in the Linux world (and beyond), is reserved for infrastructure stuff that's clearly so much better than the alternative that pretty much everybody decides to use it. Despite actually having to learn some new tricks.

Dbus, for instance. Or udev. Or git. Or cups.

Systemd isn't quite in that position yet, but only because it requires Linux – and thus Debian drags its feet.

Mir will never get there. It has zero benefits WRT Wayland and a more restrictive license. And getting Unity to run on Wayland instead of Mir is probably not THAT difficult.