Add a shortcut to iCloud documents to the Finder sidebar for easy access
I was just trying to add iCloud’s Mobile Documents folder to the Finder sidebar for easy access and was flummoxed that it can’t be added by drag & drop.
Apple tries to remove access to iCloud from the normal user as much as possible. You “feel” that when navigating Mobile Documents the ↑ (up) command doesn’t work properly, but back does. Don’t know where they’re going with this.
For the time being, you can still add iCloud to the sidebar by using the shortcut "Add to Sidebar (⌘T)” from the File menu.