I don't think anyone has said that accidents are lessened and driver skills are increased by the use of winter tyres. Least if they have, I've missed it.

From my point of view, if it shows where I live, chances are I'll never get my car out and up to the main road, on account of it being block paving that is never gritted, and it being a 90deg turn out of my parking space directly up a hill. And if I did make it to the main road, I have another hill to clear before getting out of the suburbs. So for me, the winter tyres make the difference between being able to use my car or not. Granted, it might only snow for a couple days per year, although we have seen snow fall and last for much longer than that, but as I've already mentioned, the snow is only part of their use. They are much more sure footed in the lower temperatures, and infinitely better in the wet, which we get a lot of over winter too.