I've worked in Ams for few months, about 15 years ago. And I've seen car-bike accidents there too. Not sure what do you mean by "excuse".
Cars and bikes are not equal, that's right, as well as small sedans and large pickup trucks are not equal, motorcycles and cars are not equal, semis and pickups are not equal, etc, etc, etc. So what? There're rules of the road, California Vehicle Code in my case, and everyone using a public road should obey one, period. Having a car driver more responsible for safety of those around him doesn't mean that bicyclist can cut in front of this driver while running a red light against the traffic and consider himself to have a right of way just because he's a weakest player on the road.
I totally get the American argument in favor of the right to bear arms, but at least that's based on the assumption of responsible gun ownership.
When it comes to cars however, any sense of responsibility seems to go out of the window. Cars and bicycles aren't equals, a car is a heavy piece of machinery that can kill a grown man in an instant. The driver of a car has a much, much greater responsibility to the safety of those around them.