To be fair, it's not always true. Many APIs actually don't have NSError argument and throw Obj-C exceptions on actionable errors. For example, reading from an N

To be fair, it's not always true. Many APIs actually don't have NSError argument and throw Obj-C exceptions on actionable errors. For example, reading from an NSFileHandle may throw NSFileHandleOperationException. I suppose, in most cases it has been done for brevity. Though, you can also argue that only opening a file could fail (due to invalid path or insufficient permissions).