Well, I'll agree with you dandruff. There doesn't seem to be a really good reason to me. We get plenty of snow here, and I rarely bother with the driveway, unless it interferes with the car driving down the driveway. A couple people mentioned that it's hard to stop if ice forms in their driveways... what do they do? Turn into the driveway at 50mph? We have no, nada, none pedestrian traffic on our driveway.
However, I keep the sidewalk clear almost all the time, and put down extra salt to help make sure no one's going to slip.