This. Also bzr. They seem to want to control their projects completely and so even when they have good tech they lose out to more open, community developed, equivalents that build wide engagement and momentum.
I honestly don't understand it, you would have thought they would have learned by now that they don't have the engineering resources to do everything by themselves.
Compare that to Red Hat who always try (and sometimes even succeed!) at developing projects with the community and are far more successful at getting their projects adopted (I know people don't like them, but you cant deny they are effective at it)