... history shows that the majority of Americans will reject a non-private sleeping accommodation
However, the majority of passengers on Amtrak overnight trains DO ride in coach, so I'm not sure what history is being cited here. In fact, the majority of overnight airline passengers also do not reject non-private sleeping accommodations.
As far as pricing...it's time for Amtrak to recognize that the availability of real, quality, freshly prepared food service adds value to all classes of tickets
That may be true for some passengers, but not others. Most Amtrak passengers, even on long-distance trains, are traveling a relatively short distance and may not be riding through meal times. Others find it a better value proposition to bring their own food, and that was true even before Amtrak started downgrading the dining service.
And why the obsession about the need for "freshly" prepared food? Outside of 4-star expensive white tablecloth establishments and maybe some hole-in-the wall ethnic joints, most of the food sold by the American food service industry is pre-prepared. This would be especially true of on-board food service because of limited space and the general higher cost of labor involved in hauling your work force all around the country. Pre-prepared food can be good, and Amtrak food and beverage deserves criticism for the low quality of the "contemporary flex" dining, but it is possible to provide decent pre-prepared food.
and so it's appropriate to take some amount of that ticket revenue from all classes and cross-subsidize the food service so that the price charged on board reflects the marginal cost of preparing that meal. Stop bundling all meals with all sleeping accommodations, but do have an upgrade option for first-class passengers (say, 'Sleeper plus' and 'Parlor plus') which will include meal coupons. All others pay (the marginal cost) for whatever meals they choose to select.
And, while you're at it, let's look at restoring real food service to day trains over a certain trip length (say, 6 hours or so).
Alas, the experience of the airlines has shown that a transportation enterprise can be successful without having
any sort of meal service, or meal service on the order of Amtrak's "contemporary flex" dining. I found this out on my intercontinental flight to Beijing, where United Airlines served me food in coach that was the absolutely worst food I've ever had on a transportation carrier. (Not all of it was bad, the the "breakfast" they served towards the end of the PEK-IAD flight was absolutely inedible. But it was hot and it had eggs and sausage, if that's important. Yecchh, I would have preferred the Amtrak breakfast sandwich, or even the sugar-bomb oatmeal, muffin and yogurt. Heck, a Clif bar and a cup of coffee would have been better.)
I agree that Amtrak needs to pay some more attention to making its premium class service on long distance trains attractive enough to keep the premium class accommodations as full as possible. The higher revenue per mile from the premium classes does help cross-subsidize the overall service. But keep in mind that the reason for government support of long-distance trains is to provide mobility for people who can't or won't fly or drive and to serve rural communities that don't have convenient access to other forms of transportation. It's not to provide experiential rides for people nostalgic for the golden age of rail travel, at least not unless Amtrak can show that they can make a whole lot of extra
net revenue from such service.