Earlier quoted context omitted.
In contrast to undocumented free (open) systems? Documentation is an issue irrespective of prorietariness(??!) of a system. I welcome this initiative. (Yes I know there are examples of documentation excellence to be found in some free/open systems. You can advocate their use whilst also having well documented macOs.)
There is no undocumented open source software, the documentation is just in a technical language. This is why learning to program is important, as it also means learning how to read the documentation. I'm not being factious. We always say that documentation doesn't keep up and that the only real documentation is the code. Ultimately the only reliably documented software is free software.
Unless we start writing paragraphs of comments for every little five line function, there will still be a need for technical documentation outside of code.