why is zeus upset with mortals and what examples does he give?

Zeus believes the mortals to be at the root of everything bad....

"Ah how shameless--the way these mortals blame the gods.

From us alone, they say, come all their miseries, yes,

but they themselves, with their own reckless ways,

compound their pains beyond their proper share." (1.37-40).

Zeus says that when man encounters miseries, they simply blame the gods. Zeus takes no responsibility, and claims that the miseries of man are born in their own human nature. Thus, man creates his own problems.

Example; Odysseus made his own decision to go to Troy. This decision was responsible for the events that took place afterwards. Odysseus had only himself to blame for his wandering, and that same wandering was the direct cause of the suitors taking advantage of his household.