I have nothing to add that hasn't been said already about the "why" but I can tell you a fact. I made a baby quilt for my niece's son (who turned 3 in June) and that quilt has been lugged around and washed so many times that the machine applique (close blanket stitch) has started to ravel and come undone but the hand stitched binding is as intact as the day the quilt rolled off the presses. Go figure.