The author of Shulchan Aruch, in his capacity as the author of Shulchan Aruch, is often called "the m'chaber", or "ham'chaber", literally "the composer" or "the author". (Obviously, many authors are called that when discussing their books, but the m'chaber is often called that even out of such context. For example, when discussing halacha, one might mention that the Tur holds a certain view while the m'chaber holds another and the P'ri M'gadim a third.) While of course Shulchan Aruch is an important and seminal work, there are other works equally important and seminal.
How did it happen that the m'chaber came to be called that?