It seemed like a bad bet before the season.
Alabama quarterback Tua Tagovailoa never had started a college game. He remained in a quarterback competition with Jalen Hurts, even if it seemed he was very likely to win it. Alabama has run the football often under Nick Saban. The team's defense deservedly gets a lot of credit for its success. And even last year, Hurts and Tagovailoa shared a healthy number of reps, especially in blowouts.
Also, the return on a winning bet was relatively small. So, the only way to a positive expected value was if you thought Tagovailoa was a once-in-a-lifetime type quarterback at Alabama.