I've only been once, but my experience was similar. Got to the theater maybe 15 minutes before showtime, was greeted by the waiter who was very friendly, put in an order for a beer and some popcorn and chips and queso. Nothing arrived until 15 into the movie (so 45 minutes from order). None of these things require much prep beyond dumping into a bowl or pouring into a glass.

The people next to me ordered some sandwich or something, and around the time my food was arriving, asked where it was, only to be told they were out. I assume if they hadn't asked, they just wouldn't have gotten anything.