Frankly, after looking at Ben Lowy's iPhone photography work for work for Sport Illustrated, ESPN, Harpers, and a host of other magazines, I am of the opinion you literally don't know what you are talking about. You are seeing what your bias WANTS to see. . . and not what is actually there. There are some very beautiful photographs on his website.
A pro camera has sophisticated focusing capabilities, with several selectable points throughout the field of view which can be manually selected using a joystick while composing the shot. This is essential for proper focus while tracking a sports player on a crowded field, or an animal in the brush.
A pro camera has dual sets of controls for shooting in portrait or landscape mode. You can adjust key settings like aperture, shutter speed, etc. while composing using the knobs/dials.
A pro camera has the battery life to shoot a couple thousand shots (even allowing for some review from time to time).
A pro camera can write to two memory cards simultaneously for protection. Sometimes cards go bad, and that's your only backup in the field until you can get the images copied. You need to be able to pull out the full cards quickly and put new ones in as needed.
A pro camera can take different lenses.... telephoto, wide angle, macro... and depending on the quality (and cost) of the lens, you're going to get different results. More expensive lenses are "faster", have image stabilization, have pleasant bokeh and better edge-to-edge characteristics (distortion, etc.).
An 8MP iPhone 5 image is only so big... you're not going to get the same quality LARGE prints with that as you would with an 18MP or larger image.
Those are just a few points which an amateur might be able to understand... I could go on, but even you should get the point.