Outhaul control: why around the gooseneck?

The outhaul upgrade pulls the a line from the clew, through the eye at the end of the boom (sometimes (always?) with a double purchase by first attaching to the eye, then through the clew, and back through the eye, as opposed to a simple bowline at the clew that feeds through the eye a single time), then forward along the boom to the clam cleat, doubles back to a trucker's loop or a thimble once for purchase, then back through the cleat, which appears to be recommended on the starboard side...

Outhaul control: why around the gooseneck?