Nurseries have strict staffing ratios to adhere to so if the don't have the staff, then they have an issue in regards to safety.
They also have to make sure that they are taking the health and safety of staff and children, and so if they have to close, they have to close.
As parents we make a choice as to whether to be SAHP or WOHP, both choices are valid, but if we choose to use childcare facilities then by and large they are privately owned businesses.
Its not a business you go into for the money, and it's not a well paid career either. nursery owners can probably afford to pay their staff for a couple of months at best, and like us, they have to pay the bills.
If we don't pay anything, then it is likely that many will close permanently, with staff losing their jobs. Then when this crisis is over there will be far fewer nursery places.
Childcare costs a fortune, whether you are delivering it or paying for it, but unless nurseries qualify for insurance due to loss of earnings then if we as parents don't pay at least something there's no guarantee that your nursery will survive.