As a business owner, the property their business resides on is private, belonging to them. It is their responsibility to maintain and secure. No one else will if they fail to do so, because it is their property. It would be wise on the owner's part to include the property in the insurance policy. Even if it's detrimental, they should be required to, because no one else will (or can, lest they be trespassing on, or tampering with, private property).
Business owners always have the bottom line in mind. And small business owners often struggle to provide insurance to their own employees due to financial constraints. However, business owners should also be requred to carry an insurance policy that covers the value of their property. By doing this, they are ensuring their own peace of mind should some catastrophe occur.
Business owners know their bottom line better then anyone and they should not be forced to spend money that they don't have or to take on a policy that they don't want. However, should they not carry insurance or an adequate amount of insurance, then they should bear the full responsibility of repairing the damage.
There are consequences to every action and every inaction. Businesses have to take responsibility no matter what. Forcing people or businesses to carry a piece of paper that ensures they are being responsible is a white lie. Insurance, no matter what the coverage says, doesn't always pay up, are always looking for a reason to not pay because they are a business as well, and will only pay if you take them to court. Insurance or no insurance, lawyers and courts and madness will happen.