What becomes a problem because floor is dirty?

I once worked with quality person to prepare customer's audit. He said:

"This time our customer will visit two of our suppliers, I need to tell them to make the floors clean of their plants. Maybe should hire housekeepers by the time customer will come..."

I was curious why he said 'hire housekeepers', because I thought that normally plant workers would like to keep workplace clean.
But the quality person knew floors of both suppliers are dirty, and workers there were not willing to clean the place by themselves. That's why he said hire housekeepers by customer visit.

Well, hiring housekeepers would be a temporary solusion, but not permanent one.

I think better way is workers at manufacturing plant are willng to clean the floor.
Maybe managing people should think to encourage workers so that they will love their workplaces.