I don't drive, and get around on my bike or public transport in general. However, while arguing about "how it's possible to bike in winter with proper infrastructure" my friends pointed out the important portion of cars - "comfort when it's -15C outside with wind chill". I didn't actually have any arguments against it, and that seems reasonable.

Personally, I always can fallback to public transport if I don't want to cycle, but it's not possible in most of NA. Unfortunately, retro-fitting most of the cities to have proper subway/bus system that would complement the cycling infrastructure. But hey, I hope that day comes at some point!