I've lived in several places across the country, as far north as Quebec, and south to Nevada-- the only time I saw this practice being used widespread was in the lower midwest where freezing rain is common. I spent five years in St. Louis / Southern Illinois area, and learned the hard way why you should raise the wipers. I once had my wipers frozen into a layer of ice a half inch thick. Required 20 minutes of effort to free them. Even modest freezing rain created a challenge to free the wipers, even with the car warming up. Now I know why my co-workers practiced the wipers-up anytime there was a snow/freezing rain forecast.
In snow climates, I leave the wipers down. You have to scrape the snow off the windshield anyways, it's not anymore trouble to knock ice/snow off the wipers. Spent most of my years living in Vermont and Colorado, have never witnessed anyone leaving their car with the wipers raised.