Why do so many people take time and effort to be ugly to one another?  **ugly being used as a verb, not an adjective  Everyone has some pretty.
you still used it as an adjective. used as a verb would be "why do people take the time to ugly each other". what you did was change "be ugly" (which already is a verb) into more of a transitive verb by adding "to". anyway, the reason people are ugly to each other is either for survival, by mistake, or for revenge. with survival being the most common, mistake the second most common, and revenge the least common