It's really not dumb. It's not that simple a decision. Getting the ball again after the first 2 possessions is a valid strategy because at that point it's first team to score. Had the TD play to win failed, then KC has a decision to make, to they kick the FG or go for it on 4th down. If they kick the FG, then SF gets the ball and only needs a FG to win. If KC goes for the TD on 4th and fail, then SF wins.