Black ice and bicycles

I don't get the whole ride your bike through the winter thing. Is it that thet completely reject fossil fuels? And if it is health, well how healthy is a crash on black ice. A friend of mine rode all winter. He crashed. Inevitable. So how about saving bicycles for nice weather. Take a walk. Ride the bus. Yeah you have to sit next to strangers. Hey. Would it kill you? Could you muster a "Good morning!", if you had to? It's hard enough to WALK on black ice. I mean, come on now.