Explanation for newbies: The GNU/Linux copypasta is an argument made by Richard Stallman that the operating system should be referred to as “GNU/Linux” or “GNU+Linux” because linux is just the kernel and what makes it useful are the various GNU programs and libraries like coreutils and glibc.
Alpine Linux is a linux distribution that ships without any GNU software (though it can be installed using the package manager).
And that’s why Alpine should be considered harmful. Copyleft is important, folks! musl and BusyBox are just ways to facilitate even more enshittification, Tivoization, and other corporate abuse than the GPLv2 kernel already does by itself.