I think the reasons for this are pretty simple: it's the prevailing mythology surrounding cars in America. Most Americans have been indoctrinated to believe that bigger = better, especially with respect to safety, but also as far as utility (they even call the biggest passenger cars "sport UTILITY vehicles"). Of course, we have to ask where that mythology came from, and the answer is basically car marketing and cheap gas prices that made it feasible for American cars to be marketed in that way (the marketing would have fallen flat if gas were $7+/gallon). The U.S. is one of the only industrialized countries that continued to pursue a cheap gas at any cost economic strategy after the 70's oil crisis, and this sort of marketing is a natural development given that fact.

That's why I think that counter-propaganda is needed. The car companies are constantly bombarding people with misleading propaganda in favor of big cars, selling the idea that a big car = freedom. So there needs to be some counter to that, or people will continue to believe it. Some of the anger we experience on the road, I think, comes in part from this fundamental clash between what the car companies PROMISE Americans that their car will deliver to them (freedom, excitement, independence, safety...) and what the reality is (that the roads are congested and clogged with traffic, that commuting is a soul-crushing burden, that our cars are constant money sinks, and that our cars take the lives of 40,000 of us per year).