A well-run hotel was the inspiration for the operation of many long-haul luxury trains in the extra-fare all-Pullman years. The people who rode those luxury trains were those who not only expected the best of everything but who could afford service in the same style they might have encountered at the Waldorf-Astoria or The Savoy in London. This is undoubtedly why the railroads had to have real China in their dining cars.
It should be pointed out that, back when food was served on real China in the dining cars, people dressed up when they went to the dining car to eat. (In Europe, people still dress formally when dining on a train.) In today’s world, many people wear jeans or other casual clothing when traveling and think nothing of doing so when eating in the dining car. In this informal atmosphere, why should anyone be concerned about Amtrak serving meals on informal plastic plates?