Well, it's not courting imminent death if you're sensible like you say, but I don't think that quite translates to "no reason at all not to go out in a car". Particularly if the 6" of snow is happening in a city, it can easily slow down traffic to the point of causing jams and gridlock, and every car makes the situation worse. Imagine someone who needs an ambulance to get through to them in those circumstances. Not adding to the problem, that's a reason not to go out if you don't have to, I'd say.