And what happens if a non-asshat hits it because they're dodging a person, deer, dog, or having a heart attack?
Same as if they hit any of the various other things found along roads that don't give way easily; oak trees, concrete culverts, parked trucks, Chuck Norris, loose cattle, bridge abutments, trains, buildings, etc.
Simple rule; when you're controlling a couple tons of steel moving at high speed, that is your first priority. I've known plenty of people who have had heart attacks, and none of them reported going instantly from condition white (which you should never be in while driving anyway) to 10/10 unbearable pain. In fact, two of them were driving at the time and were able to pull over safely.
As for dogs, if the owners don't keep them out of the road, they're speed bumps. I will not risk losing control of a vehicle to save an animal; I'll brake and/or swerve as much as I feel safe doing, but if there's a risk of a skid, Fido is buzzard chow.
People in the road vary. They rarely teleport instantaneously into the middle of high speed roadways, and on lower speed roadways, it doesn't take a high performance vehicle to stop quickly. It only takes browsing through the stories of cyclists, pedestrians, farm equipment and horse-drawn buggies hit from behind when a driver "couldn't get enough room to pass safely" to figure out that a lot of drivers really are asshats who don't consider slowing down until there's a safe passing opportunity to be an option.