Because it's SOOOO likely for you to have kangeroos run out in front of your car when you're doing the school run....
Well, maybe not kangaroos, but kiddies, certainly. Maybe we oughtta start calling them kiddie-bars.

I own a 4x4, but I have taken it off road. Oh, and the first time I ever got behind the wheel of a car was in the winter, on a snow and ice covered road. Moron SUV drivers, you get what you deserve.