I did a couple of quick searches for Amtrak vs. flying.
The Amtrak train costs about $90-100 if you ride the 21 hours in an ordinary seat. A "Room" costs about $400-500.
You can fly to Chicago for as low as $39.57 if you're willing to take a layover for a total time of 6 hrs. 53 minutes. (This flight only has a layover of less than 45 minutes but flies New York -> Fort Lauderdale -> Chicago. Get 2 "meals" I suppose though.) A non-stop flight is $110 and takes about 2 hrs. 40 minutes.
So ... this means that the airlines are paying customers $80 to go to Fort Lauderdale for four hours.