It's because they didn't clear off the original snow in time and it turned to ice during the next storm. Ultimately, tho its because they'd rather be lazy than be safe. I drove around my block for a better spot in between the storms and forgot my brush. Cleared the essentials and went like 500 feet at 15 mph before getting home and clearing the rest off. and i still felt like a dick the whole time

Not sure what's wrong with those people going on the highway with sheets of ice stuck to their roof