Well, in LotR, the Orcs were created with evil magic, so they'd be evil no matter what, and in Oz, the flying monkeys obeyed the witch out of fear (some cheer when she is killed, I think). What bothered me in Redwall was that when one of the bad animals is born into Redwall and raised the same way as the good ones, he still turns evil for no logical reason. The exact opposite happens later, when a 'good' animal is raised by 'evil' ones. For no reason, he turns good.
And it always bothered me that all the cool animals were evil.