I don´t care about fracture, I´m an end user. i just want a system that serves my needs. I want to use my smartphone as my desktop computer. At this point Ubuntu is the only one to give my needs a go. If they feel Mir is the way to go ... So be it.
The whole Linux-ecosystem is based on fragmentation. I use Ubuntu since 5.10. I´ve tried many other distributions. I´ve used KDE, GNOME, XFCE, ... I don´t see no reason why Canonical should not develop their own display server. if they feel Mir is the way to go and wayland isn´t ... I´ll be happy to believe them.
Some day a new distribution will rise. They may bring a new system which is better ... Then I´ll be happy to switch to them but for now there is only 1 that serves my needs.