We bought Holland Rusks for my mother-in-law, who was conceived in Holland and spent her early years eating Dutch foods. Holland Rusks are now used, if at all, as a platform to put other things on, not as a stand-alone food. She eats them plain. I understand her comment: "They taste like sawdust, but they're familiar."
An elderly daughter of Swedish immigrants informed us one Christmas season that she was hurrying home to make lutfisk for her husband. "Does he like it?" we asked in amazement. She paused. "No, but he doesn't think it would be Christmas without it."
For my mother, also of Swedish extraction, all comfort foods were based on thickened milk: cream-dried beef; an impossibly bland Welsh rarebit that was nothing more than milk-and-melted-cheddar poured over Saltines; tapioca pudding, or rice pudding with a little cinnamon. (Those remain comfort foods for me as well, along with Campbell's cream-of-tomato with Ritz crackers in it.)
I wonder if fast foods have become the comfort foods of the following generations. McDonald's french fries are not very good. But they continually top the "best fries" charts, and I love them, too.