I fully agree. That's why a stable API is needed. But there might be legitimate concerns to not expose such an API as it could impede development. For example,

I fully agree. That's why a stable API is needed. But there might be legitimate concerns to not expose such an API as it could impede development. For example, Java intentionally doesn't offer a stable API to extend the compiler. Therefore, Project Lombok has to adapt to each Java release as the OpenJDK project can and will change the compiler's internals at any time.