Germany drove to Moscow as fast as they could and they failed to take Moscow because of Russian resistance.Do not many experts assert that Hitler changed focus mid-campaign from taking Moscow to inflicting an economic defeat? What is your explanation for the push towards Leningrad if you believe the Germans were driving for Moscow "as fast as they could?"
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1