I'm going to guess that you followed the crowd and went left instead of right when you got off. The trams meet in the middle (basically a V) and the outside are the exits. The middle part is open and you can go back and forth.
All they have at 70-99 is Nathans, Auntie Annies, Starbs (which has half of the usual food options and are always out of most of it) and an ice cream place. Then there are two table service places but who has time for that? If those don't work you can always grab a gross packaged sandwich or sushi
We much prefer to just buy on the plane. I really miss flying Southwest or Jetblue...they use the good gates. OMG....the Southwest gates at BWI have a place that makes fresh crab cakes.