Much of the time, tailgaters are aggressive and even angry. They ride right up on the back bumper of the car in front of them because they want to pass or they want that driver to speed up -- even if they're already going at the speed limit. Other times, they tailgate when they feel like they got cut off and it's a way to retaliate against the other driver. It may be the first step toward road rage.
These drivers are very dangerous, and they do cause accidents. That said, it's important to remember that not all tailgaters are angry or malicious. Sometimes, they're just confused about the laws or safe driving practices. They could also be completely ignorant of the danger, not understanding that it's going to be their fault if they hit the car ahead of them.
Say that the driver in front suddenly sees an animal about to run into the road. They slam on the brakes to avoid hitting it, smartly not wanting to swerve into the oncoming lanes. Unfortunately, the tailgater runs right into the back of that car. There's a good chance that person could get out feeling confused and even angry at the leading driver, assuming they caused the crash by hitting the brakes when the reality is that it's almost always the second driver's fault. They must leave enough of a stopping distance to avoid a crash in an emergency, no matter how unexpected it is.
The lack of understanding around safe driving tactics could put you in the hospital, and that's when you need to know how to seek financial compensation.