Some do care. It's easy, as noted, to neatly part the hair on the side, slick the bangs/fringe back, and fasten it down with an attractive clip. You can also use a pretty hair band if it will stay on or go with the costume. I also will braid/plait the bang/fringe hair close to the scalp beginning at a deep side part (French Braid) and then back into the rest of my DD's hair and pull it then into the bun at the back. Her bangs/fringe are long enough for that option.
Students who study ballet like my youngest daughter have the same dilemma due to the requirement by traditional teachers to have hair completely off the face. We found it, frankly, easier to grow the hair out, but, in this case, the need to secure it back on a regular basis made it an onerous task. Just doing it for the occasional comp ... not as big a deal.