Allow hiding non-public classes in Application Explorer.
For example, I want to hide UserGuidClass, because I can't use it anyway. It's internal, therefore it can only be used from inside its package, but I can't add anything to the package, because it doesn't allow customizations.
It's not very important in this moment, because there are just a few such classes (no legacy code could use this feature), but it will change as new code utilizes internal classes for information hiding.