In my workflow, I don't ever use or have a local `master` branch. I create new branches with `git checkout -b my-feature-branch origin/master`. After I've created a revision on this branch, executing `arc land` finishes with the active branch at a newly created `master` branch, which I have no use for. I find a local `master` branch annoying to keep up to date -- I may as well just branch from `origin/master`.
Feature request: `arc land` finishes with the active branch pointing to `origin/master`, or at least it finishes this way if there is no local `master` branch before executing `arc land`.