Most of Meta's groups' approach to FOSS is throwing piles of sticks over a wall. They don't even check code can build, that it doesn't have some internal-only dependencies, and don't even care if they break other groups' code. The timeline for very minor bug can also be on the order of months to years because everyone working at the business is focused on shipping "impact" to keep their job when the next performance review/layoff round comes along.
And that's... fine. They're still giving away their code, and anyone is free to step up and mke sure that it builds or that internal dependencies are replaced.
And it's a completely standard situation for non-corporate open source software, too. OpenSSH, for instance, has OpenBSD-specific dependencies and can only be run on Linux because of the porting efforts by a separate group of volunteers.
Sure, it'd be event better if they went out of their way to facilitate external participation, but they don't have to. Not even GNU does so for everything they publish!
tl;dr: There's a spectrum of FOSS varying from performative crap to usable.
You're conflating the differing treatment of projects where there is much investment and community usability like react, ones that are half-assed like edenfs, and the zillions of others that aren't even explained clearly what they do or what they're for.
> anyone is free to step up and mke [sic] sure that it builds
On thrown-over-the-wall projects, there's too many inside-baseball gotchas and little/no documentation. Effort by others are generally unrealistic and a waste of time that won't be merged since there are rules and limitations for community contributions. The vast majority of tiny and obscure projects, MAANG code is useless to average people working on average problems because the burden to make it work is as much or more than reinventing it themselves.
> or that internal dependencies are replaced.
This is hand-waving away reality. No average engineer for reasonable effort is going to be able to reproduce an undocumented API for unreleased kernel extensions/FUSE/etc. for Mac, Windows, and Linux to make edenfs work.
Another case in point: Hack. No documentation and no portable build instructions/toolchain.
React and react native are in a different class where there is meaningful community participation and investment. Whereas hack, edenfs, and chef cookbooks is/was mostly thrown-over-the-wall stuff. There are a few projects in the middle like watchman that update code using an opaque internal->external export process without a whole lot of documentation or clear changelogs, but it's still semi-useful.
The spirit of FOSS is cheapened by flooding the zone with too much stuff on the side of crap. It's better to release less stuff that's well-supported with meaningful community engagement rather than create noise. But if you're fine with a blizzard of noise that isn't useful to anyone else, that's cool for you. Everyone is free to do what they want to do, even if it's trying to make partially-released stuff work when it would've been faster to rewrite from scratch.
