I've been driving for a few decades and have seen many serious injuries and fatalities, but not a single serious injury or corpse in a rear-end crash...
You've never driven in heavy stop-n-go traffic on the freeway in SoCal then. I have seen cars so smashed you could not tell what the make or model of the vehicle was; sadly I saw a fatality just this summer, a mother and her kids on I-5; people just don't realize that drivers will slow and change lanes to take the exit at Camp Pendleton Traffic will back up there all the way up to the freeway lane.
Not sure why you want to believe that a rear-end accident is nothing to worry about.
For God's sake, stop researching for a while and begin to think!