Yes, it's down to the writing, but the writing is not meant to show that Pike is dumb, only that he's been paralyzed by the glimpse he has had of his future, because it's made him ultra-cautious and...literally paralyzed.
Basically, it's meant to show that it can happen to anyone... you, me, all of us... none of are MEANT to have a crystal ball. Most of our decisions are made not blindly but with an eye toward the present circumstances with just a feeling of what it can lead to in the future. Pike's special knowledge of what can happen to him (and to others -- there's a reason why we were shown Hansen's son and Pike's inquiry whether his son was there with him at Outpost 4) has paralyzed him and taken away his ability to act.
Hence, at the end of the episode, he tells Spock what he does and has a talk with Kirk. He has accepted his fate and is willing to work TOWARD it, not away from it. THIS is now a revitalized, reality-driven Pike, not the scared/scarred Pike.