Shutting a city down for a day *guarantees* huge damages. Let's look at Boston. There are 240,000 households, each with a median income of $70,000/yr. Let's use a really simplfied model, and say that there are 365 days in a year - so each day is about $200 per household in wages. That means that shutting down the city for a guarantees a loss of $48 millon.
For salaried workers, that's a loss for their employer. For hourly workers, that's a loss for the to the household.
Without a government intervention, people would have gotten to make their own judgement calls. And they could have made that judgement call based on the weather information this morning, not what we had yesterday afternoon. Based on the actual weather, lots of people would have said "lol, no - I'm not going into work today". And others would have made the completely reasonable decision that they could make it to work fine.