Polytheism is more rational than monotheism insofar as it gives a better explanation for the existence of evil?

As polytheistic religions have God's both good and evil ie Hinduism. In monotheistic religions God is all good and loving etc. But then how can one account for evil? How can evil come from something so pure in it's goodness. It's like saying fire came from water. Something that is only good would not wish to create evil as then it would be inflicting harm. Agree Disagree?