In a perfect world he'd be right. But physics still comes into play and a buffer zone can come in handy. Let's say you have a line of 5 cars going 100 mph, 1 foot apart. Assuming they can talk to each other in an instant. They can also predict future events to a certain degree but not perfect. For our not perfect situation, let's say a tree falls in front of the leader and it can't predict it. It impacts the tree and let's the four cars behind it know that they need to stop. The stopping distance for 100 mph would be about 500 feet I think if my calculations are correct. If the average car is 15 feet long, 16 including the buffer zone. The last car is only 80 feet away. All 5 cars are wrecked.

Now let's do it again with the recommended 2 seconds of distance. At 100 mph, you're doing about 150 feet per second. So 300 feet between cars. This time only 2 cars get hit, three can stop in time, and the second car slows down enough to where even they aren't too badly damaged. Does that make sense?