I just never saw a reason for the Pac-12 to eliminate themselves which was always the risk. Sure Utah and SC should have won their games to prove that they were the best team in the conference but those weren’t the stakes. It was always the faint hope that by beating someone you had usually already played that year would be enough to overcome the bias of the committee towards other conferences.
Just like the article you linked to the other day: Utah won the conference in the regular season in 2019 outright. SC did also in 2022. The benefit of getting those teams into the playoff would have rewarded Oregon and Utah with Rose Bowls and added about 50 MM to the conferences coffers. Instead Oregon and Utah still went to the Rose Bowls but the playoff money went elsewhere.