* Most US roads are not bicycle ready. They weren't designed to have mixed vehicles, they weren't built for it, and they don't do it well.
* Cyclists have been given a right to be on these roads, which can't safely handle them, by legislation.
* Having them there does impede traffic that the road WAS designed for.
* The US culture has devolved lately into a "my rights" based one.
* Both the car drivers who have historical precedent with "rights to be there" and the cyclists with the newfound legislative "right to be there" willfully fail to recognize the rights of the other.
* Both sets of drivers blame the other for the lack of adherence to safety and traffic laws. Both are correct.