I could physically demonstrate to you on the court how a simple errant pass by maybe 3-4 inches off a players hot spot causes both a higher percentage of missed shots and forces that teammate to have to correct the ball each time each costing time and accuracy. I know we count assists on teams that lead to scores, but I for one as a coach would like to have someone chart each pass we throw by location at the receiver and the results. I think you already know the answer to this one. Some of the worst violators of this rule are the best shooters themselves. I was taught as a young player that this even has a psychological side to it.
Shooters tend to be selfish.
A poorly passed ball can't be shot, which means more shot attempts over time for the shooter. I want that player on my team. As a coach I would find a way in practice and even games to signal this kind of consistent passing effort. So coaches, there is my two cents worth on improving your shot release time. Shooter faster has little to do with improving percentages, but eliminating these time consuming errors will give your players longer and better looks at the basket.