Why is it, when I take the dog out early in the morning in snow or ice, that the cars I come across in ditches are, almost without exception, 4 X 4's? I'd say that the owners think that they've got an invincible vehicle, whereas in icy conditions they can often be no better than any other car.
I would say because of feeling overconfident and not respecting the road conditions because with a 4x4 they feel they can drive through anything. If you don't know how to drive in the conditions, it doesn't matter what you are driving.