I don't think anyone is saying to fault all cars that crash with bikes. Here in Portland at least, the police do not investigate crashes that occur between cars and bikes unless the paramedics on scene determine that the cyclist has experienced a class 1 traumatic injury. Also, there has been more than one crash this summer where the motorist was at fault, the cyclist was not and was either killed or injured, and all the motorist received was a $242 ticket for their traffic infraction. Personally, I would like to see it more clearly defined in the law that if a motorist hit a cyclist who is killed or seriously injured, and the fault clearly lied with the motorist, the charge automatically becomes something more serious than failure to yield or stop. If the cyclist shares the fault, there should at least be a thorough investigation to determine if the motorist should be charged beyond the traffic infraction.
I would never want to see a motorist be charged when the cyclist was clearly the only one at fault. That said, I don't think traffic law here in Oregon really does much to acknowledge that person driving a car is also someone handling a deadly weapon. It seems like people drive their cars with this general idea that if they do something that results in a crash, it's not their fault that someone died or was injured because they didn't mean to do it. I think changing that perception would make for better drivers and safer roads for everyone. How that change should occur is the stuff for arguments like the ones in this thread.