Apple, to my knowledge, never sold a mouse with a wheel. Their first mouse with scrolling was the Mighty Mouse, which used a small trackball to simulate a touch surface. It was spring mounted and would fall flush when scrolling oven a sensation similar to the Magic Mouse (this is my favortite mouse and the one I still use today). The Magic Mouse extended on this idea by replacing the ball with a multitouch trackpad.

In either scenario, “natural scroll” feels like you’re pulling on the surface which maps directly to sliding on the screen.

It makes less sense if you think about a wheel pulling the page beneath it.