As much as we hate to admit it, and knowing that some posters here were around for the SP Automatic days, Amtrak should really have vending machines in the lounge cars. That is in addition to the attendant and counter!! Not in place of them; they would be stocked with bottled beverages and bagged snacks rather than dry goods and heat-and-eat food (including coffee.) It leads to better accountability, better availability of food during break times, and generally a better environment.
This would also be a great place to implement a customer loyalty program. How often do you hear they sold out of something in a cafe or diner? Like every darn time.
If a customer loyalty program were in place, they could see by rider and more broadly demographic what is popular, and prevent running out of stuff that could otherwise sell more and increase the contribution toward covering the losses in the cafe/diner.
I have a friend that deals with this in consumer package goods (IE the stuff we buy at Kroger/Walmart/CVS/gas stations) and this work is very advanced and useful. Why Amtrak doesn't use it is beyond me, but not surprising.