Question

Why does Zeus agree to Helios's desire for revenge?

Answer 1

Helios agrees not to go to Hades and shine his light on the dead if Zeus agrees to punish Odysseus and his crew.

Although Odysseus warned his crew not to eat the immortal cattle and sheep of Helios, Eurylokhos urged the other crewmembers to sacrifice and eat Helios’ cattle saying that it'll be OK if they build a temple to Helio when they go home.

Zeus agrees if Helios shines over mortals in the fields of grain he will help Helios get revenge by throwing down one white-hot bolt to make splinters of their ship in the Winedark Sea.