What the word for comparing two things but saying one as bad other?

There isn't one single word that perfectly captures the act of comparing two things while explicitly labeling one as bad and the other as good. However, here are some options depending on the specific nuance you want to convey:

General comparisons:

* Contrast: This is a neutral term for highlighting differences, but it can imply a negative connotation if the context suggests one thing is inferior.

* Disparage: This emphasizes the negative aspects of one thing while praising the other.

* Differentiation: This focuses on the unique qualities of each thing, but can imply one is superior based on those differences.

More specific terms:

* Criticize: This implies a direct judgment of something as bad.

* Condemn: A strong condemnation suggests the thing being compared is morally wrong or unacceptable.

* Denigrate: This suggests an attempt to lower the reputation or status of one thing compared to the other.

Figurative language:

* Black and white: This metaphor implies a stark contrast between two extremes, where one is clearly good and the other bad.

* Night and day: Similar to "black and white", this emphasizes the significant differences between two things.

Ultimately, the best word to use will depend on the specific context and the tone you want to convey.