Some people have to go to work anyway otherwise they would lose their job and some jobs are critical such as ambulance, nurse, surgeon etc and they have to get to the job.
But there are some people that just want to get out even though they don't need to be at work and risk going out just because they want to and they shouldn't.
I stay home if I see some severe winter weather in the forecast. Not worth it for me to risk getting stranded and dying or dying in a car crash or causing someone else to die in a car crash.