Dirty warehouses deliver a message to your employees. Even though it might seem minor to have some dust on your shelves, enough minor oversights like that add up to a big, negative message. If it’s permissible for there to be a lot of cardboard on the ground, then employees, consciously or not, begin to believe that being lax in other ways is permissible, too. It’s a lot harder to take pride in your work when no one respects the appearance of the workplace. What’s more, when people work in an untidy environment, they tend to do untidy work.