Because Prometheus stole the fire from Zeus without Zeus permission.
Now was Zeus mad on Prometheus and he maked a plan to get revenge.
Zeus gave Prometheus a wife and her box.
When he didn't stole the fire but just asked than there is no Pandora and the box.
No Pandora who was so curius about everything and want to touch it.
No evils like envy, Jealousy, old age, spite, vanity, distrust, despair, proverty, deceit and disease that make the world unhappy.
Now hope must save the people from the evils.
