Shoes do get dusty (or sometimes muddy) when tramping around the 'games, but that's no reason to look like a tramp. I usually knock the dust off my shoes a couple of times at the 'games (a hankie is perfect for this task) and, if they get muddy, I pour a little water on them to rinse off as much of the mud as possible.

Either way, it is the polish that prevents the shoe from letting down the over all look of the outfit and protects it from both dust and mud.