I am so sorry to hear of your friend's terrible loss.
I think the problem is, that a lot of 20 year olds (particularly boys) are immature and still think that they're invincible and that nothing bad will ever happen to them, whatever they do.
When the state punishes them, they just react as if their mother has told them off and just don't seem to see that they are being punished/restricted for a really important reason. They simply aren't mature enough to recognise the consequences of their actions, or learn from their mistakes.
Perhaps the problem really stems from allowing people to drive at too young an age.
Eventually, this 'kid' will presumably grow up and realise what he has done to an innocent young family; but that will, obviously, be far too late for your poor friend.