Mark & the gang thought they could build something better and so they went for it. Their ideas may be wrong, but they took a stab. Most of those criticizing Mir never go beyond mere talk. That's the main difference to me.
After 6-9 they revealed what they worked upon and made loads of incorrect statements about Wayland. Obviously this resulted in pretty harsh response.
Wayland is quite usable in Fedora as well as various other distributions, so your "never go beyond talk": eh? This while Canonical delayed Wayland by not announcing they wouldn't help out with Wayland anymore.
Anyone who knows open-source hackers should know that their bullshit detectors are highly attuned to typical political malfeasance, and the transparent overlays of conventional corporate politics are not going to work on them (other approaches would work supremely well; hackers are not invincible).
I'm actually worried about Canonical after their repeated political failures. Despite their best efforts, Red Hat continues to stomp all over them, with systemd winning over upstart and now Wayland over Mir.
They need to re-evaluate their strategy for land grabs. Do they not have the technical skill on staff to conceptualize technologies that get people on board? Is Red Hat intentionally undermining them (hard sell since most of these projects existed before Ubuntu decided to try to copy and win), and if so, how can they compete?