Psytenance writes about the Fundamental Attribution Error and how it applies to transit users vs. drivers, but I think it could as easily be applied to cyclists. The fundamental attribution error refers to the tendency for people to over-attribute the behavior of others to personality or disposition and to neglect substantial contributions of environmental or situational factors. So when drivers imply that cyclists ride because they're environmentalists, or Lance-Armstrong wannabes or self-righteous, they're attributing the decision to personality instead of assuming that cyclists are making a rational decision. And when cyclists state that drivers drive because of car culture or laziness, they're making the same mistake.
It is, in my opinion, a statement about empathy and how hard it is to understand the actions of others. Of course this doesn't apply to taxi drivers - those guys are just crazy.