Baders, I have law enforcement and emergency room and EMT personnel in the family, so you don't have to scare me with horror stories. I've heard all the nasty stories, seen tons of accident site photos, and had people close to me in horrible accidents. I know what happens to meat in a car crash.
But with all due respect, you only view accidents after they already happened, and my understanding is that your training is medical not technical, so I would not put much stock in your assessments of accident causes.
Speed increases the amount of kinetic energy available to damage occupants in an accident, but it doesn't really make an accident more probable. There are many other factors to consider as others in this thread have noted.
In any case, the whole point of automobile travel is to get from point A to point B in timely fashion. Risk of death or serious injury may increase as speed of travel increases. But obviously the risk is acceptable in light of the time saved - or else we would walk everywhere. It's really of question of how much risk are you willing to take on in return for reduced travel time.
For my part, I keep my speed low enough so that travel is sufficiently safe for me. I don't have accidents that have anything to do with speed. I don't even get close to having accidents that have anything to do with speed. If the safe speed is higher than the speed limit, then I am going to violate that limit when circumstances allow.