Chinny, you have made me smile.
I think that plain shirts look strange without pockets much of the time. They look even stranger if they are made from polycotton, as then their tendency not to crease at all makes the shirt like an unreal expanse of smooth, unnatural colour. I don't really like plain shirts on a man anyway, but for a work shirt I think pockets just help to break it up. of course, it doesn't matter under a jacket or any other garment, but if you are wearing a shirt alone it sometimes makes the shirt look a bit cheap if it is just straight, plain, not pocketed.
You don't have to actually
use the pockets, but they just give the eye something to settle on, and hide pokey-out nipples when it gets cold.