It seems to me you are forgetting that the defense constantly puts Romo in a come-from-behind, obvious passing situation in the 4th quarter. That and Garrett's refusal to run the ball and protect leads.
Quick question...does it occur to anybody that Romo wants to be in that kind of offense? His KILL-KILL-KILL moments could just as easily be dominated by his desire to change the play, misreading of the defense or the like as much as dummy Garrett refusing to depend on the run.
Parcells had it right with him. He has to be controlled and managed. He has got way too much autonomy over the years and at this point he is set in stone. Sorry, he's not a special talent in terms of reading defenses etc., like the great ones. That is why he can be baited into INTs at the worst possible times.
He always thinks HE has to win the game. Look at his whole football life. Always the overachiever. But he was the best player on bad teams. He does not know any other way. And perhaps that shapes how he is now that he has matured.
Always "battling" and "fighting". He subscribes to the loser mentality that "football games in this league are hard to win". So he presses because he thinks that he has to (or even wants to) be the hero. When you press, you take risks instead of taking the play and starting over again.
He is a pretty fascinating psychological case study because honestly, he is not an elite athlete. I don't think he has a special skill or quality that you can say is at the top of his profession other than the plays he makes when he goes into Pimp mode. But the way this organization, and he himself, believes, you would think he is a little too arrogant thinking he is elite, even when deep down, he's still the little Cinderella story, coming out of nowhwere...about ready to win, the Master's Championship. But he never makes it in the hole.