There are many kitchen implements that would be as useful, if not more so, for this purpose. A ladle and a pan come to mind spontaneously. However, at least in modern stories, the rolling pin seems to be the instrument of choice. How did this come about?
Follow up: would the formation of this stereotype have anything to do with the different types of rolling pin? For example, the French style which is simply a tapered stick, versus the American style with a handle run through a hollow cylinder?
The French style I would imagine is easier to wield than the American, which would wobble as you swing it around.