1. Trusting Atlanta's judgement
The same front office that drafted Penix didn't trust the quarterback enough to give him the reins. Atlanta signed Kirk Cousins before drafting the rookie quarterback and did everything in his power to keep the veteran in the starting lineup. Atlanta's front office hasn't changed since they hung two entire seasons on Marcus Mariota and Desmond Ridder. Even Raheem Morris pointed out that he was unlikely to have the head coaching job if not for the issues at quarterback.
You haven't changed the decision-makers who believed in Mariota, Heinicke, and Ridder as starting options. The fact that they had Desmond Ridder in the building for a full season and believed he was their best possible answer is beyond concerning. It is the only real reason that fans have for any concern over Michael Penix Jr.
There is no denying that Penix has far more talent than any quarterback the Falcons have brought in as their answer. Perhaps it is more reassuring that the Falcons didn't believe fully in Penix and put him into the lineup in year one. No matter where you fall on Atlanta's front office it has to be at least noted their recent track record at the position.