Basically, traditional dining cars are an absolute money pit due to labor costs. Of course there are other factors as well, but the labor costs are what makes the issues insurmountable, IMO. Including benefits (a gold-plated health care plan and essentially a defined-benefit pension in the form of Railroad Retirement), the SAs are probably about the highest-compensated waiters in the world. And for operational reasons, especially during delays, the crews spend lots of time on duty being compensated when the diners aren't actually open and serving customers.I would be interested in knowing more specifics of your perspective on the economics of the traditional dining cars vs. "flexible" dining, if you're able to provide more detail.
Huge built-in inefficiencies and costs that regular restaurants don't have to deal with.