POSIX is a standard.

Windows has yet to provide a consistent way how to obtain the OS version across releases. Then we can maybe talk about standardizing apps communications.

Uh, that may not be the best example. Are you aware of a reliable way to retrieve the OS version across all POSIX OSs? Because if you are, I would love to hear it.

Probably, but MS is a single vendor, with one (sort of) brand of an OS. They have full control over it.