That seems unfortunately unsurprising. With shorter vehicles (sedans), when you get hit (as a pedestrian, bicyclist, motorcyclist), you are more likely to be pushed over the hood of the car. But with a taller vehicle (truck, SUV), you're more likely to either be propelled forward after hitting the high, flat face of the grille, or get pulled and dragged under the vehicle.

While going over the hood is going to hurt, and can kill you, the other options are much more likely to kill you.