To me this is a cop out.
"Changing who you are" IS a necessity of being a great coach. You style, schemes and situational decision making has to be pliable, not rigid.
Knowing the gravity of the situation, what's going on in the game, what your opponent is doing, who has the momentum, all of it matters.
And yesterday when SF had all the momentum? Had the crowd in a frenzy? Your team was gripping, dropping balls, missing tackles, looked gassed? You kick the damn FG to grab some momentum back and stop some of the bleeding.
So nah, people are just saying nonsense if they're defending Campbell, and all the other over-analytics coaches who continue to put their teams in bad spots to lose games. Especially one of this magnitude.