That depends. Oathbreaker is more than just a fallen paladin; its someone that turns their back on their oath to serve a vice-driven agenda of some kind. Its appropriate for someone that's so driven by thoughts of revenge that they'd lose their faith and turn their back on everything they once stood for in order to achieve their vengence. Or consumed by another desire (killing a man to take his wife is a historical classic, as is a paladin noble consumed by greed). People are driven to such deeds by greed (for money or power over others), love / lust (yes, you can become an Oathbreaker for the sake of cherished family), or anger. You need these kinds of driving motivations to become an Oathbreaker.Yeah, but wouldn't it make a far more interesting story to have a classical lawful good who somehow falls and sees his powers from the oath of devotion warped into that of the oathbreaker?
It makes no sense for someone who just slips up and makes mistakes to develop a power called Aura of Hate. Dreadful Aspect channels negative emotions in a burst of magical menance. This kind of thing isn't appropriate for people who aren't consumed by more selfish emotions. Someone that breaks a classic Oath of Devotion because they grew tired of fighting and gave up challenging evil is hardly appropriate for the Oathbreaker subclass.