I'm not really following the "commits" but rather following releases. In the last 2 Years Kallithea had only 1 minor release (https://pypi.org/project/Kallithea/#history) 0.3 -> 0.4 without many new features. RhodeCode had 5 minor releases (https://docs.rhodecode.com/RhodeCode-Enterprise/release-note...) and multiple bugfix releases. I'm aware not all features in comparison are free, but we use the CE free version and it's enough for us at this point.
Actually 0.3 to 0.4.1 is a major release with many changes including new mercurial versions and better git support with updated UI and celery for background tasks. If you see a new ssh feature is just added with documentation.
Kallithea is pretty easy to work with and extend. We recently updated and built a CI using buildbot. Rhodecode and Kallithea have diverged enough and are moving differently. Also its a Software freedom conservancy project so it will be supported, hopefully it can attract bit larger community.
On a side note on this. I think Unity had their own fork of Kallithea with some changes that aren't in the official version ? Or those features are backported later from the Unity release
As you said it's sad but fortunately we have Rhodecode. In my previous company I was using Rhodecode plus mercurial and for developer working with it was a pleasure.
Now in current company we using Bitbucket, we'll think then to moving to rhodecode because we still want to use Mercurial
