The same crowd who pays up for train accommodations probably would prefer complete privacy (me). I wager I’m not the only one, especially in long distance. There is definitely a difference in feeling from an ULH flight to a LD train. Privacy matters, and if it doesn’t for some people, I probably wouldn’t wanna be seated near them anyways.
The only place I can imagine Delta one style working is the NEC, with a plausible LSL if that train ever gets its act together and shortens trip time.
On the subject of Viewliners, this whole thread continues to highlight the sad truth:
Amtrak desperately needs more sleepers and varied cars, and only ordering 25 VLII sleepers is a massively short-sighted move.