Bug 57629 Hierarchy view shows too many types [type hierarchy]
Try opening the hierarchy view on the org.eclipse.ui.internal package. You end up with tons of types. It's not obvious why many of the types are being included. I have a working set with only 10 types from this package selected. Yet there are hundreds of types in the package hierarchy view, including interfaces which doen't even have implementors. So you get all of these root interfaces which are grayed out with no children. Even the class "Action" is showing up under Object, grayed out, without any subtypes present in the working set.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/TraditionalHierarchyViewer.java
public TraditionalHierarchyContentProvider(TypeHierarchyLifeCycle provider) {
			super(provider);
		}
		
		public int getExpandLevel() {
			ITypeHierarchy hierarchy= getHierarchy();
			if (hierarchy != null) {
				IType input= hierarchy.getType();
				if (input != null) {
					return getDepth(hierarchy, input) + 2;
				} else {
					return 5;
				}
			}
			return 2;
		}
		
		private int getDepth(ITypeHierarchy hierarchy, IType input) {
			int count= 0;
			IType superType= hierarchy.getSuperclass(input);
			while (superType != null) {
				count++;
				superType= hierarchy.getSuperclass(superType);
			}
			return count;