Maybe so, but my interpretation is that there's personal opposition to change and improvement from people like Linus or TGLX or other greybeards. At least in the linux kernel world. The contribution by email is an antiquated approach and needs to go.

Now, knowing the HN crowd this comment will become grey in 3... 2... 1...

Largest open-source software, perhaps Chromium or Android, uses Google's proprietary systems with Git.