Counterexample: the Linux kernel.
Which leads to problems: see systemd.
Also, to be clear, Linux is relatively small compared to Google or Microsoft, or indeed many corporations codebases. Someone could conceivably read the entire Linux kernel codebase. That's not true for BigCorp.
I beg to differ.
Right, a single book has on the order of 4-500 pages, longer ones have more, but we'll take the average, and an average book has....30 lines of text per page, so 13500 lines per book. That makes the kernel ~1000 books, which is a lot of books, but avid readers do read 50+ books per year (my father probably does close to double this). That makes reading the entire source absolutely possible, in the order of 10s of years, which is a long time, but then, the kernel has been around for what, 25 now? So there are a number of maintainers who have been around long enough to have read through the entire kernel.
Compare that to google, where[1] there are almost as many unique source files as the kernel has lines (though to be fair, many are autogenerated).
[1]: http://cacm.acm.org/magazines/2016/7/204032-why-google-store...
Its not a permission to do work, its permission to merge the results of the work to master. Those are different.
>Google's design document culture is bad.
Then why do we have JEPs, PEPs, and rfcs in perhaps every other major project out there?