> suggests a lack of commitment to the open-source model.

I literally chuckled when I read your comment. It sounds reasonable to flatten commits before a release, as I, and others, who are hacking on code litter their history with "fix this" / "fix that" / "asjhdasjd" / "f**".

Open source model doesn't mean version control transparency. Open source model could also be development done in a private fork, and release commits dumped into a public repository.