Because government bureaucrats function from the mindset of control and directive.
They do not care how much work they make for you, but they are imperative about you NOT doing things that highlight them negatively.
I absolutely agree with you about the logic; what other market can a customer tell you unilaterally they are going to pay you less AND that you cannot seek out the balance of transaction from the other parties to the transaction.
It is price controls and a misguided belief that they can control the market by directive. In human history, it has never been successful for long, and it is another marker for the end-stage of a system.
The salient question is what comes next.
