Nice, didn't know the origin of that.
In the age of type setting, commonly used letters were stored in the closer to hand, lower case, whereas less used letters such as capitals were stored in the upper case.
Italics has nothing to do with meaning slanty text, it's named after it's country of origin (Italy) and was developed to fit more text on a page.
Oh and the fact that blew my mind this week, your mother is a 3D printer and your father was just provided software.... (No offence or pun intended, just quite a true analogy I thought)