Why did Movie Rita go bad?

[Movie Ranger]

With all the evil behavior she shows, its hard to believe she was once a Ranger. Zordon says she turned evil because she wanted more power. It has too be more complicated then that. Why did she turn evil?

[Kimberly Hart]

She must have been a mean girl like Kimberly.

[Decepticon]

She wanted the power to reshape the universe as she wished. And saw lifeforms on Earth as inferior. Thus inconsequential to her plans. The other Rangers wouldn't let her do this and stood in her way.