That's the standard line, but I have never felt that as a user. Debian and FreeBSD feel about equally integrated to me as systems. Some stuff in both is develop

That's the standard line, but I have never felt that as a user. Debian and FreeBSD feel about equally integrated to me as systems. Some stuff in both is developed by different upstreams (large parts of both the Debian and FreeBSD base installs are developed elsewhere), but the "buck stops here" when it comes to integration, integration-testing, engineering a consistent user experience, and generally making the system work for end-users. If anything Debian feels slightly more tightly integrated to me, though it depends on whether you frequently use a lot of non-base packages. FreeBSD's model is tight integration of the base install and light curation of everything else in userland, while Debian's model is to "Debianize" everything in the archive and ensure it plays well together, even non-base packages.