I think what he meants by human and users is "programmers" and layers of abstractions in your code. The ability to change and go deeper when you need it.
But you example works nicely as well, you should avoid having to work at lowers abstractions, and limit the work there as well. "changing the core to adapt to new features rather than adding to the core"
But you example works nicely as well, you should avoid having to work at lowers abstractions, and limit the work there as well. "changing the core to adapt to new features rather than adding to the core"