I know that most things cost more in Canada, (except Prescription Drugs!) but VIA Employees make about the same as Amtrak Employees, so the costs to run a Diner shouldn't be that dis-similar.
I've ridden Amtrak since A-Day and during the Rainbow Train days the Food and Service was excellent on most LD trains.( you Paid for all food and beverages then).
A downward spiral began when the Carter cuts started in the 70s, then sort of leveled off. ( don't remember when the meals started being included in the Sleeper Fare, early 90s???)
The Simplified Menu Fiasco in the 90s was another disaster.
Then about 2012 the Menus once again started going more upscale with the Excellent Chef inspired meals and with good deserts.(the Veggies and Rolls still Sucked!)
For about two years things were really good in the Diners until Boardman made his ill advised and impossible promises to Mica and the Congressional Mica Managers.
Once the nickel and dime cuts began, things went downhill quickly and we ended up with the current bland, generic "National" Menus,Diner-Lites and No Diner at all! ( partly due to the extremely delayed Viewliner Order) .
Hopefully the New CEO will reverse this sad state of affairs and once again make "Dinner in the Diner" a pleasure that all LD riders look forward too! YMMV