Got Pus? Can someone help me understand why this food is such a treasured commodity?

This is just gross. Can someone help me understand why this food is such a treasured commodity? The FDA allows 750 million pus cells in every liter of milk (about 2 pounds). In 1 pound of cheese 7.5 billion pus cells are allowed, that is b/c it takes 10 pounds of milk to make 1 pound of cheese.