Cars sort of create that problem because the mode of transportation separates people in boxes, where we can't hear or see each other. All other drivers are idiots, right?
Compare this frame of mind to the Dutch bicycle intersection where both directions are green at the same time.
Or the famous Shibuya pedestrian crossing.
These get soo many more people from one side to the other than cars can ever achieve.
Even if people where nicer in traffic, cars can not navigate this fluidly. They're simply too big and drivers can't adjust speed and direction fast enough to do it even if they had the space.
He did say Americans, but anyway it's a valid question for other countries too.
In Denmark we just introduced the draft for women too. I'm not sure what my girls are going to choose when they get old enough. We do have to the option to deny it simply by claiming to be pacifist, so I'm not worried, just curious on what they'll choose.