Normally everybody goes to the bowl games. I would think your kid is a little irked they don't get to travel to a bowl. It's just a normal game for them 🙂
People made fun of BYU taking buses last year to the Potato Bowl. But they took the buses so they could also take Wives, Kids, Parents (parents could ride the bus, but had to pay for their own hotel), Admin staff w/spouses, Coaches wives/kids... basically everybody. Players could also got the option to fly home directly from Boise if their family lived out of Utah.
For the Hawaii bowl... I assume the cost of taking Wives, Kids & admin staff is why they are leaving some at home.