Did you even read it? Like always, I am grateful that Richard's still contributing towards software-freedom. He's a giant and a legend.

Git was designed to support the Internet-spanning development project that maintains the kernel Linux. Therefore, Git needs a concept of user identity that also spans the Internet, and the Git developers found a simple solution: email addresses, including an optional name.

This was an obvious choice for another reason: development of the kernel Linux is primarily coordinated using mailing lists. That project has its own mailing list infrastructure, and Git was also originally designed to facilitate processing patches exchanged by email.

GitHub evidently disagrees with these design decisions, because it not only fails to provide mailing lists, but also absolutely refuses to display email addresses in its main web UI. If a commit has an email address associated with a GitHub account, a link to that account is shown, otherwise only a name is shown with no link at all.

One of the moral principles of the free software movement is that the barriers to users becoming developers themselves should be minimal and only technical (and those are acceptable only because barriers such as requiring knowledge of programming fundamentally cannot be eliminated). Obscuring email addresses as GitHub does has the effect of isolating users from existing developers. The requirement to create an account at GitHub to participate in discussions is also a subtle social barrier to users who do not yet think of themselves as developers.

I've been unable to contact the developers of a project before as their only communication channel is Github. This is a technical decision by Microsoft to create a monopoly.

if you don't identify with free software culture is your personal preference, all issue described are real.