Actually coach the team.
If you loved the Cowboys like I do, regardless of the owner, you could still provide leadership on the sidelines. Garrett's philosophies were idiotic, at best. He seemed to think that the Cowboys would be great simply because of their history, and coaching wasn't needed.
So he didn't do any coaching. The Cowboys had a real quarterback, but they were missing the key component they needed on gamedays- a head coach on the sidelines.
Now they miss having a real quarterback, despite having a real head coach.
Dak is Garrett 2.0.