Your basically relying your life on the car in front of you.
It's stupid.
Just because you have GREAT reaction time, doesn't mean the person in front of you does.
There is a main reason why, you have to stay behind a car at a certain length.
Because no matter, how late that person brakes, or how horrible a driver that person is, you hit him in the rear, your still at fault. (although it may seem like it isn't your fault, trust me it happens to the best of us) If you were far enough, you would have time to avoid and wouldn't have hit him. Get me?
Hell, I don't tail gate, and have great reaction time. But i still get near close calls with the stupid ass drivers in front of me, or turning in front of me. You have no control over anyone other than yourself.
Remind me to never visit Miami.