The website said so.

One thing I learned about classical Greek writing; the Gods are always angry. It doesn't matter about what. They are angry. You give them dinner. It's not right. You praise them. It's not enough. You make sacrifices. They don't quite meet the requirements. They seem, from all available writing to act like petulant children. Only with beards.

Here are some of the punishments they dished out to those who failed to meet their high standards.