Any server offering DAV support is going to have a huge advantage, but implementing DAV is a pretty large task. This is not a paradigm very well suited for a largely dynamic site. Midgard is going to have DAV, but we're going to get it right, so this might take some time. As an open source project, Midgard relies on volunteer contributors. Better than one could hope for on our resources, not as good as we'd like.
Documentation is essential but rather low-profile, so many view it as a non glamorous job.
This needs more PR in general, I think. Another problem is that many people feel that they don't understand the technology, and therefore can't document it. While the documentation is still in a sorry state, I think we've got our needs covered in other areas quite nicely. Of course, having more people in the project wouldn't hurt. We used to have on our site this list of things we need help with, but I believe it is now quite outdated.