I love the low tech video and hope this project takes off. However the biggest issue I see is that git is terrible at handling binary data.
When checking out a repo, git pulls down the entire history. That means binary files added and then later removed sit around forever bloating the repository.
You should read more about how git-annex actually works. It doesn't track the files in git; it tracks the presence and location of the files, and their hashes. git-annex transfers the actual files around separately, tracks what repositories have them, and ensures that enough redundant copies of those files exist.
Yes that's how git works. However joey has made git annex, that uses git for versioning, but doesn't store all binary data in git, hence avoiding the exact problem you point out.
When checking out a repo, git pulls down the entire history. That means binary files added and then later removed sit around forever bloating the repository.