Split Top Bread

Is there any practical reason for the split tops they make on some loaves of bread and rolls? Or is it just for aesthetic reasons?

From what I read, it allows the bread to rise higher, as the split can expand as it's being pushed outwards. I believe that's also why in certain crusty breads such as french bread, they're often sprayed with a fine mist of water during the first couple of minutes: it keeps the outside of the loaf from forming a crust, thus it can expand more.