Just to throw some gas on the fire, what about all the cab, taxi and limousine services that never use winter tires but get around all year just fine? Sure they bang into each other once in a while, but if it was truly that severe an issue they'd all have them on the cars. I got a ride to the airport a while back in a town car and was talking to the guy about just this topic. He said he's never used winters, never needed them, it's just all about how you drive...and let me tell you, he wasn't holding up any traffic! You know, I could walk around all day with protective body armour on, it would be safer, but I don't think I will...our society has gotten way to focused on everything being safe, we don't have to think for ourselves anymore.
BTW, I am enjoying this debate, lots of good topics coming out here.