Why does the primary monitor have (0,0) as its upper left coordinate?

By definition, the primary monitor is the monitor that has (0,0) as its upper left corner. Why can't the primary monitor be positioned somewhere else?Well, sure you could do that, but then you'd have to invent a new name for the monitor whose upper left corner is at (0,0), and then you're back where you started. In other words, it's just a name. You could ask, "Why can't starboard be on the