Being a quarterback in the NFL is a matter of survival. Sooner or later your protection will start to break down, and very soon after that one or more heavyweight guys will be heading toward you in a determined attempt to weld you to the ground.
That being the case, quarterbacks have to have situational and peripheral awareness of what is going on around them, and either be able to get rid of the ball, or, if they can run, take off in some less dangerous direction.
The world of the NFL is full of history stories of quarterbacks who lacked pocket awareness and survival skills. One example that comes to mind is the contest at Buffalo between Rob Johnson and Doug Flutie. Johnson looked like the prototypical NFL quarterback – tall, athletic, with a big arm. He impressed the Bills enough for them to trade for him from Jacksonville and make him the starter over a little short guy from Canada. (The fact that he was not the starting quarterback at Jacksonville, and that there might be a reason for that, was lost in the burst of enthusiasm to trade for him).
The problem soon became apparent. While he could throw the ball, Johnson had no survival instincts. When protection broke down, he either got sacked, or he ran all over the place and heaved the ball, sometimes with bad results. The Bills eventually inserted Doug Flutie, who, while lacking the arm strength of Rob Johnson, knew when to take off and could make things happen on the run. Johnson’s career eventually fizzled out in a collection of injuries and short-term starts.
The Dallas Cowboys similarly inserted Tony Romo into games in the 2006 season, when it became apparent that Drew Bledsoe was not able to handle playing behind a deficient offensive line. In only a matter of minutes, Romo showed that he could work out when his workplace was about to be invaded by The Other Guys, and could make things happen despite that issue, although he also had to learn when not to desperately heave the ball downfield.
The Washington Redskins have the same issue today with Robert Griffin III. After setting the NFL on fire in his debut season, when his blazing open-field speed and playmaking ability led to predictions that he would revolutionize quarterback play, Griffin was seriously injured in his second season, and has not looked like the same player since. The injuries appear to have robbed him of his speed, which means that he now has to learn to be a pocket passer. The problem is that he does not seem to even know where he is in the pocket, and does not currently have the skills to determine when the pocket is collapsing, As a result he now resembles an indecisive statue, and is being sacked and hit at a rate that will ensure he never completes a full NFL season. The main question is whether he can learn enough survival skills before he gets seriously injured or replaced. While he may be more naturally talented than his backups, Kirk Cousins and Colt McCoy, those backups seem to have pocket awareness and survival skills that he lacks.