Which honestly underscores one of my biggest complaints when working inside Apples ecosystem. I always get the feeling that they're building solutions for themselves first, and developers second, they don't take an agnostic approach to creating a platform. A good example of this is when you look at their UIKit and Appkit frameworks, all of the components were designed to the specific behavior that Apples engineers wanted at that time, with no thought on how to easily extend them. Compare this against other frameworks that were intentionally built to be easily skinnable and customizable.