Why can't speakers be like hats or a pair of jeans? When you first buy a hat it is stiff and unmanagable, after days of wearing and messing with the bill, it takes it shape and more or less stays that way for the rest of the hat's life. It might continually become more flexible over the years (or degrade) but it will be at a very decreasing rate. The materials in a speaker driver and hat are obviously different (and thus possible irrelevant) but the principles don't neccessarily have to be.