How is he a good quarterback?
He won a few games in a row, mostly at the last gasp. He played the patriots and was destroyed. They lost the two games after that too and IIRC correctly he lost them poorly. He beat the Steelers, and played well, I will give him that. He plays the patriots again and looked like a lost lamb for most of the game.
His throwing is almost non existent, he might be able to scramble but the fact he runs mostly backwards when pressed (29yard sack anyone?) shows he doesnt know that sometimes you should just throw the ball away. The patriots have one of the worst rush defences in the league and we force him to 14 negative plays yet he is some kind of running god?
The steelers did nothing against the broncos option plays and paid the price. That doesnt make him a good QB.