They enjoy the high prices.
That is why it is dumped..................
Sorry, but I worked at a dairy, and it is not a very profitable business. According to the USDA, the average gallon of whole milk is $3.04 a gallon which is close to 2 Liter Bottle of coke. But for milk, you need *Acres of expensive land expensive cows
massive amounts of feed and water
Expensive vet services
*Milking at least twice a day
*Constant refrigeration from then on
*Transportation from multiple farms
*Pasteurization and other processing.
*Short shelf life
*Delivery at least twice a week due to the above.
*Etc.
Due to the short shelf life and cost of refrigeration, excess milk is duped to make room for more. Milk is about 97% water anyway.
Many people are ignorant of all this, and more.