USC, like Ohio State, was considered to be among the favorites to make the College Football Playoff going into the season.
The Trojans, like the Buckeyes, ultimately fell just short of achieving that goal, winning their conference championship but not before losing two games in the regular season (to Washington State and Notre Dame), which kept them out of the field of four.
So the Trojans and their fans, like the Buckeyes and their fans, have reason to be disappointed that they are playing in the Cotton Bowl instead of in the Rose Bowl or the Sugar Bowl.