It's probably true that they weren't making enough $$$ to cover costs so saying Amtrak wouldn't allow them to continue running their cars on the City of New Orleans was probably just a graceful PR way to quietly end it unless there were some mechanical or safety issues with those vintage cars that we didn't know about that would cause Amtrak to halt it. I'm sure it would have liked the extra revenue.
I've read some reports that say they only had a few passengers on board many of the trips so even though they were operating with small apparently non union staff that could do multiple tasks like be a waiter/bartender and porter on the same trip unlike the "old days" when much larger dining and sleeping car staff were required it must have been too expensive for Iowa Pacific.
I think there is a market for this type of operation in the US... Look at cruise ships (although they use cheaper foreign labor for many positions) and the private rail cars in Alaska and Rocky Mountain Explorer and the occasional Pprivate rail cars that are apparently profitable. A lot of people have money to burn for premium luxury travel. Most of the travelers seem to be older retired types but there's a lot of younger.
people and foreign travelers coming to the US that could have ridden it.
New Orleans and Chicago are both popular tourist destinations.
Pullman Rail got a lot of initial free publicity Maybe they didn't advertise enough in the right upsdcale travel publications and websites to attract business.
They're now planning charters from Chicago to Kentucky Derby that cost around $6 thousand per couple Good luck with that.
One review oin trip Advisor said the Pullman rail Journey was a good concept but poorly executed
Hope someone else can do a better job and stay in business