Only 25% of companies generated a taxable profit. So they simply don't have the funds to buy enough backup power.
If you have light loads, then yes, it is easy enough to get UPS's, solar etc. but think of the heavy industries that needs 10's or 100's of KW of power to run their machines and factories.
It would be too expensive to get backup power for this.
Also, many businesses, like shops, are prevented from installating generators etc. if they are inside a shopping centre or are tenants in a complex. The landlords stop them.