Why was Medusa so cruel to everyone?

Medusa's cruelty is often attributed to her tragic transformation rather than her inherent nature. Originally a beautiful maiden, she was cursed by Athena after being violated in her temple, turning her into a Gorgon who could petrify anyone who looked at her. This transformation isolated her and filled her with despair, leading to a sense of bitterness and aggression towards others. Thus, her cruelty can be seen as a response to the injustice and suffering she endured.