Personally, I have little more trouble riding in winter than in summer. Obviously riding in the midst of a snowstorm is challenging, but so is riding in a rain storm or excessive heat and humidity. Waiting for a bus in those conditions is no picnic either. But snow and rain fall only a few days of the year. Once the storm passes, the roads are back to normal.
For that matter, driving in snow, rain and heat are also challenging. My son has permanent disabilities since crashing a car on an icy road. He was in the hospital and nursing home for months. If he had been riding a bike, he probably would have been fine.
For me, the advantages of riding are multiple. Being immersed in all the seasons is one of the greatest joys of my daily life. As I get older, I appreciate being tougher and stronger than other people my age. If somebody feels differently, by all means they should get a car.