Not Homebrew, yes me. Just trying to mediate and meeting with as many people on both sides (past and present) as possible.

Why is homebrew involved in this?

It's not. The lead maintainer of Homebrew (Mike McQuaid) is helping to mediate the conversation between the parties, per his own post.

Has nothing specifically to do with Homebrew.

Homebrew is one of the most developer-visible Ruby projects around.