premise: On the other hand,  figurative or exaggerated expression  would probably have been a simplified improvement over  metaphorical or hyperbolic expression,  which might be tough going for someone who had to look up literally to begin with.
hypothesis: Conversely, it might have been simpler to use the phrase "figurative or exaggerated expression" rather than "metaphorical or hyperbolic expression," as this would be difficult for those unfamiliar with the word "literally."