It would be so much better if Canonical focused their efforts on Wayland. Mir is just such an awful thing for Linux in general.

I use Linux and OSX desktops every day and catching up to OSX or Windows in terms of everyday usability via reasonable graphics performance is basically impossible without the ecosystem working together.

That being said, Ubuntu can do whatever they want, it's their money and resources and they can sink it into Mir if they choose but wow, what a waste.