I certainly would not want to take away from someone else's enjoyment in travel.
Sleeping car accommodations, paror cars, dome cars, dining cars, services rendered onboard, locomotives, mail--all these and more are part of the mystic of travling by train. The famous railfan E.B. Whiteaker (whatever the proper spelling of his name is. Longtime railfans will know who he was) used to ride the 20th Century Limited from NYC to Albany just to get a haircut. Now, he could get a haircut anywhere, but it was most special for him onboard the train. That's how powerful a mystic train travel can be.
The Pacific Parlour Car does have a few special features that the usual Superliner lounge does not have. For one, history. Most Pacific Parlour Cars are ex-Santa Fe Hi-level cars that were at one time a part of the famous El Capitan trains. I got to ride in one a long time ago on Amtrak's Southwest Chief. There is a certain mystic in riding in a car that has so much history to it. Not as famous as the Super Chief, but famous in its own way.
The reason Amtrak has so many services for first class passengers is to entice them to spend more money on sleeping car accommodations--of various kinds. Certainly, people paying that much money are entitled to some special things. If Amtrak were to charge coach passengers for the passage and use of the Parlour Car, I don't think it would diminish othr passengers' enjoyment that much. If Amtrak charged for it, many people would turn away (especially children); most people will not pay extra just to go into the car. If they did, they would pay because they really would want to be there and behave themselves. People would still come in, buy drinks and or food and leave tips for the bartender--it's all still money.
It's like being in a fancy hotel (like the St. Francis or Fairmont in San Francisco or the Empress in Victoria--they are tourists attractions as well as famous, luxurious places to stay). Many people cannot afford to spend a night, but they will come in and have dinner, Sunday brunch, afternoon tea, a nightcap, see a performance in a nightclub, or such; they can enjoy themselves and make use of the services, and I don't think it diminishes the enjoyment of the stay=the-night guests. If fact, it adds to the atmosphere and mystic of these places--for everyone. Also, when people attend such things, they usually dress up and are on their best behavior.
Same thing with a first class parlour, dome, or lounge area.
On the Starlight, I know more about the train, its contents, and the countryside through which it travels than most, if not everyone, in the sleepers (and coaches). I probably know more than the train crew--they are too busy with their jobs onboard to pay much attention to what's going on outside the window, except of course the engineer in the locomotive. I familiar with the route, sights along the way, the history of the route, the cities and towns along the way (their histories), famous trains that once plied the rails. Even in the dark, I know the route.
I have seen photos of people onboard the expensive Mountaineer in Canada, for example, doing everything but looking out the window and enjoying the spectacular scenery through which they are passing. Just because people have a lot of money--more money than I do, it doesn't mean they appreciate the trip, the scenery, or the train, or know about it more than I do. I am not anti-rich, by any means. These are things that I have noticed.
I like seeing the train and the passing scenery from different points of view and perspectives (I am inspired by Impressionist artists, art and art techniques, one of which is capturing the same scene from different times of the day, perspectives, colors, etc.). The Parlour Car is six cars from the locomotives: I am closer to the motive power and can look back and see more of thet rain behind, especially going around curves. The diner is next. I can enjoy they train ride and the scenery while enjoying a fine meal from various viewpoints depending on where and which way I am facing. The lounge car is next (eighth car from the locomotives) and has its own high points. The last car of the train (a coach) allows one to see the entire train up front (rounding curves), and I can look out the rear window and what the track and scenery recede in the background, as the train leaves it behind.
As I intimated before, I am bothered by VIA Rail's policy of the Skeena (from Edmonton to Prince Rupert) of allowing only first-class passengers to use the dome car (coach passengers can use the lounge area and snack service but not the dome seats) during the peak travel season (summer). VIA Rail had this policy for The Canadian for a while. How many of those people are actually sitting there and enjoying the scenery (as opposed to talking, reading, sleeping) and the train or care anything about them? There are two of the most scenic train rides in the world. Under the CP, CN, and early VIA, dome seats were open to coach passengers as well as those in sleeping accommodations. This was true on the California Zephyr, North Coast Limited, UP's City trains. True, the GN's great dome cars were reserved for first-class passengers, but coach passengers had their own dome cars to use. They were not completely left without panoramic viewing seats.