> I don't know where the mistaken conflating of "open source" and "developed by the community" comes from

i think people confuse github with a social network and all the extra social conventions that come with that instead of just a place to remotely host a git repository. Open source is just a license model, if no PRs were accepted, all communication ignored, and no bug fixes made globally forever an open source project would still be open source. Take the code and do what you want as long as you comply with the license, that's all open source is.