I'm not involved beyond just caring a lot about Ruby.
TL;DR: I've been given a lot of private nuance from both sides here but, even just based how the two sides have treated me personally, it's very hard not to put the blame primarily on RubyCentral. I've been a maintainer on Homebrew for 16 years: it's a hard job. If in doubt: I'll side with maintainers.
> How can they remove maintainers from their own projects? If my project is yawaramin/foobar...
The official RubyGems projects in question were under a GitHub organizational account, not a single user's account. A subset of the maintainers had the "owner" flag on the org. One of those folks basically initiated the takeover. See [2] for a more detailed recounting.
[1]: Shopify, pulling strings at Ruby Central, forces Bundler and RubyGems takeover - >>45348390 - September 2025 (107+ comments)
[2]: https://joel.drapper.me/p/rubygems-takeover/#the-takeover