Developers are going to hate this, but it’s good for the rest of us.

Some, but not all. There’s no reason a developer should have to explain why they’re using UserDefaults. It’s a local-only place for storing very small amounts of data. The data is created in the app and read only within the app. There are no privacy or other concerns in its use. It’s just a tedious waste of everyone’s time to provide a reason.