In the beginning, station wagons ruled the family driveway. They were a affordable, efficient, practical way to move a family and some stuff around. For decades, if you had a family (or were a small part of a family), you probably had a station wagon. However, with the emergence of the minivan, the days of the wagon were numbered.
With unbeatable practicality, the minivan was now the car to own if you had kids. It still is, if you're smart. But smart isn't what Americans want. Americans want cool. They wanted something bigger, something more imposing, something that didn't tell everybody they had children.
Enter the SUV. The Ford Explorer, Jeep Cherokee and Chevrolet Suburban sold with their tough looks, go anywhere personality and complete lack of family stigma. They were cool, gas was cheap, and they were so tall people couldn't see the stroller in the back. However, gas is now expensive and people think of SUV drivers as selfish assholes out to kill the polar bears and burn the forests. Americans needed something new to fill the role of family car. Now that they were addicted to a high seating position, they had a problem. Wagons are almost completely out of the picture, minivans aren't cool, and they can't be seen driving a gas guzzling SUV. So they started buying crossovers.
Crossovers are, as suggested by the name, a cross between a car and a truck. They look and drive like tall wagons because, well, that's what they are. They are wagons for people that like to lie to themselves. They can sell because they are called crossovers, which makes them sound different than wagons. They don't have the gas guzzler/anti-tree stigma of the SUV. They aren't openly built around children like minivans. But they have been on the market for a while now, and I think eventually they will get the same negative stigma as the minivan and the wagons did in the past.
But what will replace the crossover?