One could argue that both cheese and cake have a standard recipe as well. Carrot cake has additions to that basic cake recipe. What is referred to as cottage cheese of the home-made variety (heat milk, add vinegar or lemon, separate curds) is then added to our modified to create other types of cheeses, Wensleydale Springs to mind as an example, or Lancashire or Cheshire. All very similar fresh cheeses. Bread being both the ingredient or a recipe isn't any different in that sense, at least that was what I thought.
Plus I thought keeping it as using bread within a recipe limited it quite a bit, hence taking it to the dough concept expanded options a tad.