Well Daniel Stone shed some light on the situation:
The background to this is that he was deeply personally abusive to most people he ever interacted with, calling us rainbows idiots, assholes, telling us he didn't care about us or have time for our unicorns, etc. This included during the review process, angrily brushing away any constructive review comments (e.g. Jason Ekstrand and Pekka on the last round of the minimisation patches) as people with agendas attacking him, or trolling. So no-one ever wanted to review his patches, because even if you did feel like helping out someone who constantly abused you, he'd ignore your entire review and call you a troll - a total waste of everyone's time. Then he'd get really upset when his patches weren't merged, despite having either zero review, or unanswered (aside from abuse) review comments that suggested deep problems with the protocol.
The only feedback he wanted was his code merged unquestioningly. Now he's got his own project where he can do that, and Wayland doesn't have someone to scare off potential contributors by abusing them for no reason, and has about the same amount of reviewed code ready for merge. I think it's a win-win.
edit: even more details: Why Scott Moreau got kicked out