The text doesn't seem totally true, for example:
> Section D.7 requires the person uploading content to waive any and all attribution rights.
Yet, from the ToS, section D.7:
> You retain all moral rights to Content you upload, publish, or submit to any part of the Service, including the rights of integrity and attribution. However, you waive these rights and agree not to assert them against us, to enable us to reasonably exercise the rights granted in Section D.4, but not otherwise.
So you don't waive "any and all" rights.
From the article:
> Section D.5 requires the uploader to grant all other GitHub users… right to “use, display and perform” the work (with no further restrictions attached to it)
From the ToS, D.5:
> If you set your pages and repositories to be viewed publicly, you grant each User of GitHub a nonexclusive, worldwide license to access your Content through the GitHub Service, and to use, display and perform your Content, and to reproduce your Content solely on GitHub as permitted through GitHub's functionality.
So uh yeah, there are lots of restrictions on it. "solely on GitHub as permitted through GitHub's functionality", so they can only use Github functionality (i.e. Forking) on your content. They can't sell your content or relicense it or host it on their own website.
The only real problem I see here is that unless you created the work entirely by yourself ("you" here can mean a group), you can't grant the rights necessary to upload to Github, even if you're well intentioned or the original authors may be fine with it. And these rules apply to private repos, too. I wish the author had focused more on that.