It's true, they do tend to think that. Which is too bad, because The Cathedral and the Bazaar has very little to say about proprietary software. esr's type-case

It's true, they do tend to think that. Which is too bad, because The Cathedral and the Bazaar has very little to say about proprietary software. esr's type-case for Cathedral development is GNU software, and the Bazaar is Linux. FOSS is 100% determined by the license under which software is released. Several notable open source projects, Lua and SQLite leap to mind, are entirely closed-development. Others are pure anarchy, most are somewhere in the middle. The polemic which coined these terms was mainly making a case that the bazaar model is surprisingly effective and worth considering, a controversial claim in its day, but no longer so.