This only applies to sleeper car routes. You're on the traib for 2-3 days, mostly with no cell service. If you eat in the restaurant car, they will seat you with strangers. If you sit in the observation car, there's a bunch of other people sitting there too.
I did NY to Miami 18 months ago having spent a week in Washington/NY and was due for 3 days in Miami before flying home.
Saturday morning in NY looking at a few sights I hadn't seen (Trinity Church), then a relaxing train down to Miami. Beat flying and spending Sunday in a hotel room.
I didn't sit with anyone else in the restaurant car, but that does sound an interesting way to meet people from a whole different world. The Friday night in NY though I did sit at a bar next to other people, so I guess that was horrifying?
Had i been that against it though there was an option to eat in my room.
Do you fly in your own private plane, or commercial where you need to sit next to other peasants?
And creeping along for hours at 25mph because you're following a freight train is frustrating in its own way, even if you have a comfortable seat and food and drink.