Which campus? That doesn't match my experience in Austin at all, where most people ate the cafeteria even though alternate options were available with a very short drive, and the food was pretty good. Maybe not as good as Google's food at the time, but probably as good as the food at Google the last time I visited. And the food was decently subsidized (I'd eat breakfast there for $2). In Austin, Moto and Centaur known for having really good food, but IBM's food wasn't bad in the early 2000s. On my team, I think one or two people packed their lunch and everyone else would eat at the cafeteria except on special occasions.
I've heard from people who stayed at IBM that the food declined to cafeteria food quality over the next ten years, which led to the cafeteria basically being abandoned because people ate out so much. But that's actually counter to the narrative in the post — IBM had decent food before Google, and then some time after Google's IPO, the food declined to became standard cafeteria food.