Comment by reassess_blind

Infinitely more damage than if not rear ended.

Don't brake check on a highway. Also, semi-trucks exist.

Emotional damage when they hit the inside of your front windshield like ground beef

If you try to brake a motorcycle as fast as you would a car, it has a tendency to flip over. And in general different vehicles have different stopping distances, so "just have the whole line of cars all panic brake at once" is going to have them smashing into each other.