In my view the core of the "drama" is about whether quoting an unpolitical statement of a person endorses the person as a whole, including their political views.
The maintainer who originally responded to the github issue clearly thinks that it does not. The reporter and Twitter mob think that it does
Whether we disagree with his political views (I hope so) and how political a project like neovim is would be questions to answer once agreement on the first question is reached
Accepting a PR from a racist is a very different thing to using a quote from a racist as advertising for your product.
If you don't want reactions to your advertising, don't advertise.
I would be very mindful about advertising endorsements from anyone at all myself.
When you put an endorsement quote on your project page, you're addressing it to a large range of unrelated people who majoritarly won't even be users of your project (yet).
It's basically advertisement, we won't ever reach some universal conclusion on what any specific aspect of it means for your project, it's all in the eye of the beholder.
It's also all social norms, the maintainer doesn't get a choice on how it will be taken.