The answer is that Amtrak is a government institution... the leadership in its departments serves the government, not the people. Amtrak is a government transport service. It's just like the post office... when the cost of the stamp goes up due to government mandate... you pay it. If the mail is lost or damaged, you must live with it.
Likewise, the products on Amtrak are the products that the government decides it will offer... and at the price they set. If they want to continue flex dining then you can take it or leave it. If you cancel your trip because you don't like flex dining, no one in the government will lose sleep over it. They don't care.
The government runs the country and the citizens adhere.
This is how this 'democracy' works. For example, Amtrak.