Meat pie derived from similar food from the Middle Ages. During that time it was popular to serve dishes that contain both sweet and savory elements. Mince pie for example used to contain actual meat. By the 17th century the French were making distinct savory and sweet courses and most English food followed the trend. However for one reason or another pies changed very slowly (Gilly Lehmann speculated pies had become a peculiarly English specialty and were less susceptible to foreign influences). For example in Gervase Markham's The English Huswife, every pie recipe contain either fruit or sugar. In the 18th century cookbooks sometimes have both savory and sweet version of the same pie. The complete diversion between sweet pie and savory pie was not complete until after the American Revolution. Thus the United States never inherited the most common varieties of meat pies eaten in many Commonwealth nations today. (Many people would argue chicken pot pie would be a kind of savory pie you can find in the US. In addition in many regions savory elements such as sharp cheddar or ham are added to sweet apple pies). On the other hand sweet fruit pies became unusually popular in the US. During colonial times most apples were grown for cider making instead of eating, but a sweet variety better for eating called Newtown Pippin were bred in America. Thomas Jefferson wrote that "they have no apples here to compare with our Newtown Pippin." The first American cookbook written by Amelia Simmons in 1796 titled American Cookery contained 14 recipes for various apple pies.

Source:

The British Housewife: Cookery Books, Cooking and Society in Eighteenth-Century Britain by Gilly Lehmann

Oxford Companion to Food by Alan Davidson

Why do you think they didn't? Not sure if it's okay for me to ask OP about his priors.