Mike McDaniel wanted to be an NFL head coach, so when the Miami Dolphins came calling, he was willing to do just about anything. That included keeping Tua Tagovailoa as the quarterback. Then he benched him for Quinn Ewers.
From that moment, McDaniel made a decision before he even had the Dolphins job. He would keep the quarterback that his predecessor didn't want. It was one of the things Stephen Ross wanted to hear, and now, it might be what ultimately forces the Dolphins owner to make a head coaching change.
The problem wasn't necessarily agreeing to take the job with Tagovailoa at quarterback; it was the insistence and agreement with Chris Grier that his new contract was worth the money.