This practice comes from Japan. In 1980s, certain companies, like Toyota, understood the importance of product and process quality. And one of the practices to ensure that everyone is 'on the same ground', and that the product under development would surely satisfy the consumer's needs, was close communication between the stakeholders and receiving the feedback.
Long story short, it was part of their broader 'Quality first' strategy. However, it is only viable if the organisation is properly managed, and all Quality management things are put into practice (the hardest part).
This is just my understanding from a book I read during my free time. My knowledge may be incorrect.
I'd just like to interject for a moment. What you're refering to as Linux, is in fact, GNU/Linux, or as I've recently taken to calling it, GNU plus Linux. Linux is not an operating system unto itself, but rather another free component of a fully functioning GNU system made useful by the GNU corelibs, shell utilities and vital system components comprising a full OS as defined by POSIX.
So... now the
rustc
borrow checker is the new video game boss that is nearly impossible to beat for newcomers, right?