Aside from people driving like madmen in the winter, I think another huge problem is that the auto manufacturer's give out crappy crappy OEM all season tires with new car purchases for the most part. For example my Acura I got a set Michelin MXM4, my friends Mitsubishi Lancer had a set of Dunlop 5000M and another friend got a set of Bridgestone Potenza RE92A. These tires are all rated as deathtraps in winter conditions on customer survey and track test results.
http://www.tirerack.com/tires/surveyresults/index.jsp
Swapped out the tires for a much better set of all seasons... no problems anymore. Maybe the government should mandate a minimum tire quality standards for new cars