the.com/impoliteness

means The quality of behavior that disregards accepted standards of courtesy, consideration, or respect toward others.

from Built from 'polite,' which comes from Latin politus, meaning 'polished' or 'smoothed' — the past participle of polire, to polish. The earliest 'polite' things were literally smooth surfaces; the sense shifted to refined manners by the 1500s–1600s, the idea being that good manners are a kind of social buffing. Add the negating 'im-' (from Latin in-) and 'impolite' is simply the unpolished version — rough edges left on, nothing smoothed down.