"As mentioned in other threads, Rodgers doesn't excuse running the wrong routes. He gives more leeway to players who drop the ball."
This quote is from Cap. And it's an important distinction. The QB has to throw the ball to a spot and must begin the throw before the receiver makes a cut or even looks for the ball. In the best case, the receiver turns his head and the ball is right there. That means the pass was well thrown and the route was well run.
Now I've still seen balls dropped in those situations. Usually when the receiver takes his eyes off the ball for a fraction of a second and looks upfield. Those mistakes are easily corrected.
But if the receiver is even a yard from where he should be, it's likely an incompletion or interception. Those mental lapses are infuriating. They can be corrected as well, but require more work.
Every receiver runs a bad route now and then - rounding off a cut, cutting late, not cutting at all. But if it happens too many times, the QB will not throw to that receiver.