The Java approach is nice because it avoids any need for DI. DI is not a widely accepted pattern. There are no DI engines that would have any support for this kind of policy-driven injection. And whilst popular in some areas of software like Java web servers, it hardly features in most other languages and areas, there are no programming languages with built in support for it and that includes modern languages like Kotlin. DI engines meanwhile have changed how they work pretty radically over time - compare something like the original Spring XML DI to Guice to Dagger3. Plus, DI is awkward when the dependency you need isn't a singleton. How would I express for example "I need a capability injected that gives me access to the $HOME/.local/cache/app-name directory"? Annotation based DI struggles with this, but with the AccessController it's natural: the component just requests what it needs, and that's checked against a policy, which can be dynamically loaded from a file, or built by code.