Price controls and subsidies have been a way of life for the dairy industry, forever. OK, not forever, but a hell of a long time....probably back to the depression.
Milk was deemed a crucial commodity (it's for the children!!) and perishable, so it behooved the powers that be (been? were?)...uh, them, to do everything they could to keep the small dairy farmers, that ringed the cities, afloat.
Times change and so has the dairy business. Economics have driven most of the Mom & Pop operations out, in favor of corporate farms with large herds and good, safe, refrigerated, transportation. But bureaucrats being bureaucrats, and corporate farms being politically active, have kept the subsidies and price controls in place........it's for the children, don't forget.