It absolutely does not mean "no manual programming or customization from the user required". It means no dirty hacks, like the ones mainstream distros employ to make some of the customization and programming unnecessary that is actually kind of inherent to the way Unix has traditionally worked.
That may very well be much less easy to work with from a consumer perspective, but from a systems programmer perspective it's the opposite way. Those hacks that allow for the ease of use in a GNU userland make programming a massive pain in the ass where nothing "just works" the way it should, because GNU programs and libraries are in flagrant violation of every specification and rule of thumb that has ever really mattered for Unices.
Also, it's GNU libc that has gone out of its way to fail to adhere to standards, not musl. GNU does not give a single crap about open standards, because they believe that whatever GNU is IS the standard, which apparently is your view as well. That's simply unacceptable for a lot of people.