Because people think these SUVs are "safer" due to their size. And then it becomes an arms race; you see the highway full of large SUVs, and you feel vulnerable in a tiny compact car, because you think they will crush you in a collision, so others start buying SUVs to "protect" themselves. These land-beasts might be comfortable but they are unsafe, take an excess and unfair amount of space on the road, consume too much fuel, and trigger arms race. They need to be regulated to death for most users.
Yes. IMHO insurance costs should have to figure in the externalities to society of their increased risk to other vehicles on the road, even when the SUV driver isn't at fault. Crashes will happen, but even when the root cause is another vehicle, an SUV in the mix increases the likelihood of a crash due to worse braking distance and increases the severity of the damage to other vehicles due to its mass. SUVs make the road measurably worse for all other users of the road due to their negative externalities.
This is one of the reasons I ride bicycles and motorcycles. I take on more personal risk, but the overall effect is a reduction in accident, injury, and mortality rates for road use.
