That's a good observation, but on the other hand, there are scores of people who never learn to use language for any of a number of reasons, and there seems to be no norm against referring to them by name.
Well sure. There are plenty of other attributes people develop that define them as human. But I can't help wondering whether parents delay calling those babies by name just a little longer than they would for a baby that develops language ability? Even dogs and cats recognize their names. If a person's language facility is so dysfunctional that he doesn't know his name, there is no practical value in trying to teach it to him, so it becomes simply a label for use in conversations with other people.
