Bill,
That is not a bad line of reasoning. Yes, it is more work to make one polished. Yes, you do need to polish regular to maintain the finish. But, it is sooooo much easier to take off finger prints and clean up water stains and other bits of grossness that affect ones trailer finish. Rub the spot with a little more aluminum polish and it is cleaned up, plus it matches right in then!
So, in summation. A polished trailer is more work but less stress over worrying about what might get on the metal and leave a stain. More work, less stress, what?
Cary