If you check the pull requests tab there's also a showcase of why some people resist putting stuff on GitHub. Most of the pull requests are low-effort tickets like "update bart.css" with no further explanation and a bunch of random changes in the diff.
Those almost certainly come from people using GitHub's web editor - the default commit message is 'Update {filename}'. I despise it, I don't know why they encourage such useless commit messages, there should be no default message because there can be no useful default.
