First, if their bleeding was really so bad, they probably should have quit and looked for a different job. Second, because most casino areas have plush carpet, it is unlikely for the blood to have come from the bottom of the foot. The bleeding was probably due to a tight spot, that bruised skin somewhere in the back of the heel, on the sides of the foot, or top of the foot. The blood may have also come from someplace in between the toes, if the toe box was too tight. In the news article, one of the podiatrists mentioned the need for open toe shoes.
Women have all different sizes and shapes of toes.
Most women do not have toes that can be easily shaped into a regular pointed toe box. They need more space, so that their toes do not get squashed. So, in fact, these women go through trial and error, frustration, pain, and other problems until they find a properly fitted pair of high heel shoes. Then, they simply wear them a lot. Over time, their foot arches get stronger and other body parts adapt to the high heels.