My opinion: it grew to a gross, large set of python and apis that, when combined with multiple implementations, extensions, and company-specific customizations, made it an unmaintanable mess that was difficult to deploy and code around.<p>So, although the author compares it with the growing k8s project out there now, at least k8s more clearly stewarded, more developer oriented instead of only for ops (with code quality to match), and doesn't feel as hamstrung by environments and dependencies (just try to run a little openstack setup on your laptop for development... very annoying for a project of such age with so many company's hands in the pot).