In his case, he held a grudge for being sealed away by the Seven Sages for all eternity, and worked to fight his way back. He conquered the Twilight Realm with Zant's help, and wanted to destroy the Light World in order to restore the power of the Twilight Realm where he could rule with absolute power.
It doesn't excuse him though, his anger; he did terrible things, and I'm just glad Midna and Zelda were able to stop him. I was glad to help.