The big thing that I think the OP has completely forgotten about trivia is that it’s TRIVIA. It’s not something that you learn in history class, it’s not a fundamental fact that you need in order to get along in life, it’s not a question that’s likely to come up in most job interviews, and dog sledding is not generally an athletic event in most high schools or universities. The thing about trivia is that it’s kinda random as to whether or not you are ever exposed to the information to begin with, and even if you are, it’s generally not something important enough that you make it a point to memorize (ie. it’s TRIVIAL).
You should never criticize someone for not knowing something which is trivial. If they didn’t know who the president was, or who George Washington was, or that a triangle has 3 sides, I can see the concern. But for most non-Alaskans, the iditarod is trivia and no survey is going to change that, even if you got a 100% response.