Control over a critical part of the stack. Canonical can bend Mir whichever way they want without waiting for the upstream to implement something or accept patc

Control over a critical part of the stack. Canonical can bend Mir whichever way they want without waiting for the upstream to implement something or accept patches or wait for releases that contain features Unity doesn't need. They implement only what they want, how they want (full-blown automated testing) and get to dictate the direction of the display server which is critical for Ubuntu across devices. Upstreams don't always share the vision and often do things that don't align well with the distro. Remember Nautilus changes a couple of cycles back. I'm not saying Gnome devs did anything wrong with Nautilus, but pointing out how it was a big pain for Ubuntu developers/users. I believe you have to control all the critical parts of your product and not live on the mercy of upstreams. Canonical is not here to donate resources to help make your linux ecosystem better. That is only a side-effect of it being a member of that ecosystem. Canonical's primary goal is to create a awesome product that can disrupt multiple markets so I would say it makes perfect sense for Mir to exist.