Were the orcs really evil though? They didn't seem too smart -- like wild beasts. Maybe they were carnivorous, like lions, and needed to eat people for food. And their 'cruelness' could be owed to environmental conditioning. Heck, even Sauron didn't have a choice in his actions! He was intentionally planned by Eru to bring discord to the song of existence, or some such metaphor. So, if anything, Eru is the evil one: he created an existence in which suffering not only existed but was necessary for his own pet scheme.
