I'm sorry, but I have to disagree with the statement that both sides have a valid argument.
Johnson may be able to play at the age of 40, but it won't be for this offense. Garrett has designed the play book for a QB with the complete opposite skill set of BJ. He might still call most of the same plays, but the defense doesn't game plan against them the same.
If our receivers run further than 10-12 yards down field, the cornerbacks let them go because they know there is absolutely no threat of Brad looking their way. That's an advantage for the defense. Any quarterback that gives the other team that big of an advantage, should not be playing.
I'll agree that the OL has been terrible at some points this season, but that was not the case against the Bucs. That can't be an excuse.
Unless our defense forces some turnovers and returns them to within field goal range, I would be hard pressed to say we stand a chance of beating the Giants with Johnson at QB. At least NY would have to be concerned with Brooks going deep so the CBs wouldn't be able to just let them go.