The author says "Rails is done" meaning, feature complete. So he wants to fork it and have you use that fork instead. Why? I don't know. If it's truly "done", why does it matter what the repository name is? The underlying code will still be the same.
> "I hope we can all thrive together"
Except DHH et al?
> "we want to continue building our web applications without feeling icky."
I didn't know you could feel so negative about the code YOU write, while happily adopting code written by the person you vehemently disagree with.