I got the impression that everyone who didn't work for Canonical thought Mir was a bad idea, so that was a rare case where there was pretty much one voice. IIRC, the best case for Mir (if it had shipped on time with no bugs) would have been basically at parity with Wayland, which was started years earlier. This justifies claims of NIH.
The Snappy/Flatpak situation is different because each system has its own advantages and disadvantages and Snappy didn't come years after Flatpak.
The Snappy/Flatpak situation is different because each system has its own advantages and disadvantages and Snappy didn't come years after Flatpak.