Going Green

AITOOW is confounded at how long they have to wait at a green light to move? I understand that there is a slight delay between cars, but, doesn't it seem that we could all step on the gas at the same time and we could all be moving forward the second it turns green? We all catch up to the car in front of us anyway. Shouldn't the worry (of ramming the car in front) be greater when we know we are going to stop (red light)? Seems like people race into these stops. Do we expect that the guy is going to jam on his brakes at a green?