There's also Linus's personal aversion to how GitHub implements many opinionated workflows.
> I don't do github pull requests.
>
> github throws away all the relevant information, like having even a
> valid email address for the person asking me to pull. The diffstat is
> also deficient and useless.
>
> Git comes with a nice pull-request generation module, but github
> instead decided to replace it with their own totally inferior version.
> As a result, I consider github useless for these kinds of things. It's
> fine for hosting, but the pull requests and the online commit
> editing, are just pure garbage.
>
> I've told github people about my concerns, they didn't think they
> mattered, so I gave up. Feel free to make a bugreport to github.
