There are a lot of complaints here about the fact that Amtrak is run by former airline executives. I don't agree with all the complaints, but here's something I do find confusing. The airlines have created out of thin air ways to create incremental revenue - mainly the creation of more classes of service. "Economy plus" isn't really all that different than economy. Same seat, same seat width, same number of people in the row with you, the only difference is a few inches of leg room. And for that, there's a hefty markup.
Now I'm not asking Amtrak to start nickel and diming people for every ounce of service. The point is that the airlines discovered there apparently is demand for an in-between level of service from economy to business or first class.
The topic of services between coach and sleeper on Amtrak have been thoroughly discussed on this site, so I won't belabor that point. I just find it really odd that the airline folks don't see the market opportunity here. Though in fairness, I'm just saying random stuff and have zero market research to back me up!