"The Cathedral and Bazaar" is orthogonal to open source. Its argument is that open source is most valuable when paired with the bazaar model, not that the cathedral model cannot be considered open.

The open source definition was created in that mind. It does not state or imply open development or a community are requirements.

CatB and Open Source aren't coaxial, but there wasn't a very clean separation between them either: https://www.free-soft.org/literature/papers/esr/cathedral-ba... https://web.archive.org/web/20021001164015/http://www.openso... . "[T]he same pragmatic, business-case grounds that motivated Netscape" was CatB. Even now OSI doesn't emphasise any separation: https://opensource.org/about . You are correct: the Open Source Definition does not mandate an open development model. However that's probably at least in a small part because, well, how would one craft a legal requirement for open development in a software license that wasn't either unenforceable or very burdensome and abusable? It's also quite definitely because the expectation was that forks and/or the threat of forks would in practice enforce a certain level of open development on OSD-compatibly-licensed software: this was in fact what ended up happening to GCC at least once https://en.wikipedia.org/wiki/GNU_Compiler_Collection#EGCS_f... . If software projects all largely go the way Ladybird is going now, and stay that way, then it's a crushing (though not total) defeat for what the Open Source movement promoted and what it hoped to achieve; but sure, to be clear, Ladybird remains OSD-compliant. (Not total because at least the source remains available, without paying or signing anything, for bug-hunting.)