Actually, many QB's hate the shotgun because they lose time having to watch for the ball. On a regular snap, the D is "that much closer" from the start, but he is able to watch the D from the snap until he finished dropping back. By the time he drops back he should have some idea where the pressure is coming from. Not only that but the ball is placed in his hands 'ready to go.' On a shotgun snap, he has to take his eyes off the D while the ball is headed his way, then he has to 'adjust' the ball in his hand until it is right. And, of course, there's always a much higher risk of a bad snap with the shotgun...