For whatever reason there are a lot of people that are going to be the same distance from the car in front of them no matter how fast that car is going. And those people tend to like to stay pretty close to that car in front of them. At that point it just becomes their comfort zone and becomes habit.
And driving with a greater distance between you and the car in front of you only encourages the people that bigfoot speaks of to use that car gap as an opportunity to squeeze in.
A few years ago, I was nearly run off the road by a truck driver who did not have the right of way, yet he blew his horn at me like I was at fault. I was actually traveling to see a client before a court hearing and I told him the story (not even thinking beforehand that he has a good bit of truck driving experience in his job). After confirming with me that the other driver was wrong and a complete jerk, he began talking about many situations where cars do some of the dumbest things when driving among the big trucks.
One comment he made = if he maintains a certain distance between his truck and the traffic ahead of him, it is because he needs at least that much empty space
when carrying a full load to safely stop -- should an emergency arise. But other cars see that large gap and decide to 'fill it', which requires him to slow down even further to regain the assured clear distance those drivers just took away. It becomes a vicious cycle and really was a pet peeve of his.So keep that in mind when you pull in front of a big truck on the highway! Give him some good space before you decide to do it.