I've been following this thread with great interest, but until now, have not had sufficient time to adequately add my 2 cents worth....
First and foremost, railroads are for-profit corporations, not "for the benefit of the public" corporations like PBS. The first, last, and all in-between goals of a corporation, by design and intent, is to make a profit. Any portion of that business that doesn't make a profit is either terminated or sold off. Failure to remove losing operations may ultimately cause the failure of the entire corporation.
While most of us here would like to believe that a railroad is here for the public good, or to play the role of "benefactor" to society, that is clearly neither their purpose nor their goal. Their business is to carry cargo/merchandise/whatever from A to B, and get paid enough to pay all the associated costs for doing so, and make a profit (plus bonuses for the bosses). If they can make $1000 profit for moving a container from, say, Los Angeles to Chicago, then moving 2 containers = $2000 profit, etc. I don't have a clue how much BNSF or UP makes for moving one container, but it's clearly obvious that the =profit= to the railroad for moving a trainload of containers from LAX to CHI =far= outweighs any profit they may gain from moving one Amtrak train from LAX to CHI. Add to that any "lost opportunity" with having to hold a high-paying freight train for perhaps 20-30 minutes until Amtrak comes by adds =cost= to the freight-train (fuel, payroll, depreciation, wear-and-tear on the loco), not =profit= for the railroad. If Amtrak were to disappear tomorrow, the railroads would definitely benefit economically.
Oh, and by the way, the second goal of any for-profit corporation is to make MORE profit this year than last year.
Secondly, sorry to say, but if all the LD trains were gone tomorrow, it would not make any measurable impact on traveling public whatsoever. OK, 10 gas stations will make an extra $40 sale on a tank of gas to someone driving LAX to CHI, and, maybe after 1000 or so people drive it, GM may sell one new car as the result. Would Greyhound or American Airlines notice a loss-of-Amtrak-LD-attributable increase in their passenger business? Probably not. Even if they did, it would be miniscule...maybe 0.1% increase, easily attributable to some other factors such as bigger aircraft, a extra round trip flight, or whatever.
I've long been in favor of increased frequencies on the LD routes. At a minimum, 2 trains a day, about 12 hours apart. Preferably, though, 3 or even 4. The problem Amtrak has with its LD trains is the numbers. There just aren't enough seats available on a route with one train per day.
Using the Lakeshore Limited, for example...there's approximately 300 passenger capacity on that train. Multiply by two to arrive at the number of passengers that pass by the Erie PA station at 3AM or so. That means that of the 600 fares (assuming full trains), the entire cost of 2-3 (maybe more) full- and part-time station agents for that day, plus benefits, rent, utilities, and Eries' piece of the cost pie for general overhead must all be associated to those 600 fares passing through Erie PA. Simply adding one additional daily frequency would result in 2 trains each way with perhaps 200-250 passengers each, or 800-1000 fares per-day passing through Erie PA, as the better times would attract more passengers, too. The costs of the Erie PA station would be essentially unchanged, thereby resulting in the per-ticket amount needed to support operations at Erie would be reduced.
But, coming back to the numbers at Erie...even if every passenger on todays Lakeshore chose to drive and took I-90 through Erie, the added number of cars on the road would not be statistically noticeable. Even if all the passengers on the LD trains into Chicago chose to drive, the added number of cars would not be noticed in Chicago, either.
The numbers also work against small-town America that Amtrak stops at, like Lincoln NE, or Wisconsin Dells, WI. The populations of these small towns are not big enough to have any statistical significance, even if the entire town took Amtrak. People in small-town America have long had one travel choice...automobile. 100 years ago, the horse-and-buggy gave way to passenger trains and interurban railroads that stopped at almost every place two dirt roads crossed each other. Those gave way to the automobile as the publics' =choice= of mode of travel once cars became affordable and the roads were paved. Small-town America was the first to lose their travel options because of low numbers of daily passengers. Again, going back to the profit-motive of business...passenger trains to small towns started losing money about 1930 or so, and had to be eliminated for the business to survive. In 1971, the railroads unloaded the remaining money-losing passenger-hauling business on the federal government. And that's where it is today.
Hauling passengers on a scheduled, daily basis will never make money. That basic truth has been with us since the '30s and is worldwide. Based on the bankruptcies of the airlines through they years, even airlines are not consistently profitable.
So now, we come to the bottom line...WHO is responsible for providing public transportation, and, what kind of transportation is desired? Statistically, the number of passengers on LD trains don't even count. Even if the number of LDs were doubled, they still don't count. The federal government has, in the past, and continues to provide the infrastructure to -allow- travel, but is not, itself, in the travel-business. Independent companies provide the services, whether in the air, on the road, or down the rivers.
Unless the government steps in and starts providing big-bucks to the for-profit railroads to increase infrastructure, Amtrak, or USATrak, or any other passenger-trak will never be on a level playing field. And with todays' financial constraints in all levels of government, the money will NOT be coming.
My estimate...ride Amtrak LD trains now, they won't be around forever.