Microwave Improvements

Looking at how current microwaves rotate the food so that it cooks more evenly, I thought of another way one can improve how microwaves cook. Taking a page from the trends of innovation, how about adding a 3-D mottled surface to the inside of the microwave? I certainly understand that the smooth surface on the inside of the microwave is practical for cleaning purposes, but why not have a 3-D mottled reflective surface covered by a smooth glass easily cleanable surface? The microwaves inside would bounce around in a more erratic, random fashion, and my theory is that it would cook foods more evenly. Sure, it's an incremental improvement, but it seems like something easy to attain.