As an individual who has worked in retail for a grocery store, I believe all retailers should stay close if there is a winter/ice storm that is going to hit an area. I understand that businesses have to make a profit but they cannot be putting their workers lives in danger to come to work for little pay and no benefits. Also, customers are not going to be shopping at stores to purchase supplies at retailers knowing that the weather is bad outside. Retailers need to keep stores closed and keep employees home because it’s not worth employees getting injured coming to work and working in a store that is going to be mainly empty with little customers.
Retailers should not have to stay open when they're snowed in. The issues involved would include, but not be restricted to: the safety of personnel in transit, supply, and the fact that there aren't that many people out in a snowstorm.
Tl;dr Safety, supply, running at a loss. If they want to, it's their idea, and their idea only. They should put out a notice that they'll be closed, though.