Are the phrases "people are dumb" and "mean as hell" types of figurative language from In Cold Blood and are they adequate?

"Mean as
hell" might be classified as a form of figurative language, as it is a(a comparison that
uses "like" or "as"). This expression is a cliche, or a phrase that has
become worn out from overuse, but it nonetheless compares a person's meanness to the evils of
hell and involves a comparison that is not literal. "People are dumb" is not a form of
figurative language, as it does not use any kind of figurative (or non-literal) comparison.
These expressions are not totally adequate, as they could use more vivid forms of
description.

If you are looking for other examples of figurative language,
there is one in the first paragraph of the book. When Capote is describing Holcomb, Kansas, he
writes about "grain elevators rising as...