Why do people find traffic accidents so fascinating?

I mean the accident can be on the other side of the freeway off the road completely yet both sides of the highway have to come to a complete stop.
The first responders will be trying to get traffic moving, and yet these people feel they still have to come to a complete stop and stare at the accident, with the police there telling them to keep moving.
Do they not realize they are backing up traffic for miles?
Of course slow down obey the flag people, but stopping to stare is making the situation worse and unsafe for everyone.